The effectiveness of peer support from a person with lived experience of mental health challenges for young people with anxiety and depression: A systematic review

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The same is now happening to support young people with anxiety and depression but it is unclear what the evidence base of peer support in this population is. Methods: A systematic search was conducted with the Orygen Evidence Finder database, Embase, MEDLINE, and PsycInfo from January 1980 to July 2021. Controlled trials of interventions aimed to educate or treat young people (mean age between 14-24) to improve their mental health, which were delivered by a peer worker with lived experienced of mental health challenges were included. Outcomes related to depression or anxiety were extracted. Study quality was rated using the Critical Appraisal Skills Programme. Results: Eight randomised controlled trials with 1,885 participants were included, with six undertaken in high income countries. One targeted depression and anxiety, another targeted stigma-distress in youth mental illness, one aimed at first episode psychosis, four studies for preventing eating disorders and one aimed at drug misuse. One study successfully reduced anxiety and depression, another reduced depression only, four reported reductions in negative affect, with the final two measuring, but not having a significant impact on depression. Study quality was rated as ‘good’ overall. Discussion: Despite the uptake of youth peer support globally, there is limited evidence from controlled trials of the effect of peer support related interventions on anxiety and depression. Further rigorously designed trials of peer delivered interventions for young people experiencing anxiety and depression need to be conducted with a focus on understanding the mechanisms of action underpinning peer support. In the absence of sufficient evidence, we propose potential mechanisms to guide future research into how peer support is an active ingredient for youth anxiety and depression. Figures Figure 1 Figure 2 Background Depression and anxiety are prevalent mental health challenges, with onset commonly occurring during adolescence and early adulthood ( 1 ). In an Australian survey of young people between 4–17 years of age, 6.9% had an anxiety disorder and 2.8% had major depressive disorder in the 12 months prior, which was associated with high levels of distress, self-harm, and impacts on schooling ( 2 ). Twelve-month prevalence continues to increases; for example, in an international survey of 14,000 University students, around 18.5% experienced depression and 16.7% anxiety ( 3 ). While some young people receive help from trained professionals, a large proportion experience barriers to accessing services or do not have their needs fully met by services ( 2 ). For those who do seek help, peers play a critical part in the help seeking process for young people, who often turn to friends and family first before accessing formal help ( 4 ). The degree to which informal support from peers, such as friends and acquaintances, is helpful will depend on how capable and willing peers are to provide such support. Attempts have been made to formalise peer support for promoting mental health and wellbeing in educational settings ( 5 ). Although peer support can occur across multiple settings, there is a rapidly growing peer workforce in mental health services, especially in high income countries ( 6 ). Peer workers (also called peer support workers, peer practitioners and other terms) are positioned in mental health services and trained to draw on their lived experience of mental health challenges. In contrast to other roles in the mental health system, the peer relationship is uniquely characterised by shared experience; the value of expertise through experience rather than clinical education and training; and reciprocity/ mutuality, whereby both individuals explicitly learn and benefit from the relationship ( 7 ). Peers are responsible for establishing and continually negotiating the ‘rules’ and power structures of the relationship, unlike a clinician-patient relationship ( 8 ). Five common mechanisms have been identified across various models of peer support: lived experience ; love labour , which refers to assurance of the emotional safety and wellbeing of peers; liminality of the peer worker, describing their position between identities of ‘patient’ and ‘clinician’; strengths-focussed social and practical support , and the helper role of the peer worker, which can facilitate their own recovery ( 9 ). However, mental health services are not always favourable settings for peer support. A number of barriers to implementation have been identified, including role confusion (i.e. employers and/or peer workers not knowing what the role is and how it fits within the service), role diffusion (i.e. spending time doing non-peer support tasks), co-optation (i.e. tasks becoming clinical in nature), professional stigma (i.e. negative attitudes from others and lack of credibility), and lack of support (i.e. availability of peer supervision, appropriate training and professional development) ( 10 , 11 ). Despite challenges, several reviews and meta-analyses have assessed the effectiveness of peer support interventions for adults with mental health challenges, finding that client and program characteristics varied widely ( 12 – 15 ). For example, peer workers delivered a range of services, such as peer education, peer support, mentoring, psychoeducation, and case management, in different settings and mediums (see Table 1 for examples of peer support). Regardless, peer support interventions appear to be effective at improving hope, empowerment, increasing patient activation and self-efficacy ( 12 , 13 ). While one review ( 15 ) did not report a significant difference in hope, they suggest this could be attributed to the limited amount of included studies that focused on this, and differences in methodologies and outcome measures. Table 1 Different Real-World Models of Peer Support Model Description Delivery Methods Specific Model Benefits Example One-on-one Peer Support given between two people. Most likely involving a professional third-party to link the two people together. Face to face, Phone, Online Tailored for the individual. 1-on-1 Peer Support Appointments (Orygen; https://oyh.org.au/client-hub/peer-support-team/1-1-peer-support-appointments ) Group peer-to-peer support Groups share a lived experience. May be structured and organised, however, no formal facilitator. Can be independent or tied to a larger network. Face to face, Online Tailored to the shared lived experience. Can be informal and include social activities. Grow ( https://www.grow.org.au/ ) Peer-led groups Peer-Leaders sharing their lived experience to support and educate others similar to themselves. Can be workshops or structured group peer support often tied to a larger network. Face to face, Online Tailored to the shared lived experience, may have educational aspects. Hearing Voices Network ( https://www.hearing-voices.org/ ) Groups co-facilitated by peer and traditionally qualified expert (e.g. clinician) Often involves professional health services, where a group of people with a shared lived experience are supported by both an expert and peer. Can be structured and formal. Face to face, Online Tailored to both group and individual, may have educational and treatment aspects. Headspace centres ( https://headspace.org.au/headspace-centres/sunshine/youth-peer-support-at-headspace-sunshine/ ) Online peer support Can be one on one or group format. May have professional involvement through moderators. Mostly peer-to-peer support through forums. Online Can be anonymous. Side by Side (Mind; https://sidebyside.mind.org.uk/ ) Adapted from: https://www.nationalvoices.org.uk/peer-support-hub/peer-support-models-explained . NB: All models may be provided in either a traditional service (e.g. community mental health service) or peer-led service. Peer support interventions in adult populations generally did not impact quality of life, overall symptom severity, social inclusion ( 12 ), depression and anxiety symptoms ( 13 ), measures of hospitalisation ( 13 ), or service satisfaction ( 15 ). Mixed results were reported for several outcomes, including service use ( 12 – 15 ) and client ratings of the working relationship ( 14 , 15 ). However, more recent evidence ( 16 ) has demonstrated a reduction in 12-month rate of readmission to acute care following a self-management program delivered by peer support workers after patients had left the care of mental health crisis teams. The intervention also increased time until first readmission. This recent evidence suggests that peer support may reduce hospitalisations, an important objective outcome for health services worldwide. Trachtenberg (2013) ( 17 ) found that peer support work significantly reduces hospital bed use, with the average financial savings outweighing additional costs of employing peer support workers (benefit:cost ratio of 4.76:1), highlighting the cost-effectiveness of peer support. While these reviews focused on services for individuals with ‘severe mental illnesses’ (typically psychoses, bipolar disorder, severe depression), several meta-analyses have assessed peer support specifically for ‘common’ mental health disorders (e.g., depression and anxiety). Pfeiffer, Heisler ( 18 ) included studies comparing peer support versus treatment as usual (TAU) or group cognitive behavioural therapy (CBT) for adults experiencing depression. The peer support group demonstrated a greater reduction in depression scores compared to TAU, but not significantly different to CBT, suggesting possible efficacy at the level of established treatments ( 18 ). However, there was wide variability in patient populations, with many studies focusing on subpopulations, such as perinatal mothers. Similarly, Huang, Yan ( 19 ) reviewed randomised controlled trials (RCTs) of women with perinatal depression who received either peer support or TAU. For those who received peer support, depression scores were lower than controls, most participants reported intervention satisfaction, and it was cost-effective. Likewise, Field, Diego ( 20 ) reported that for women with prenatal depression who received group peer support or group interpersonal psychotherapy, both groups demonstrated significantly lower depression symptoms and cortisol levels (with a greater decrease in cortisol for the peer support group), despite the former group having a lower socio-economic status (SES), higher baseline depression scores, and shorter group sessions. Altogether, the available evidence suggests that peer work is a safe, effective, flexible and cost-effective intervention for adults, which promotes hope, empowerment, patient activation and self-efficacy, and reduces hospitalisations. Previous work has focused foremost on adult populations, and there is a paucity of literature regarding young people. Using both peer-reviewed and grey literature, Gopalan and colleagues (2017) ( 21 ) undertook a United States-specific scoping review of youth peer support services and research for young people under 25 years old with emotional or behavioural problems. In total, 43 articles were identified (only three were randomised controlled trials), with a range of different peer support models, including differences in the program goals, the degree to which peer workers were involved, and the roles they undertook. There was also variation within the peer worker roles, including core competencies, training and supervision received by peer workers. Outside of the USA, the CHOICE project ( 22 , 23 ) in Australia, studied the impact of youth peer workers supporting consumers (aged 16 to 25 years) to take part in shared decision making regarding their mental health treatment. Peer workers used a co-designed shared decision-making tool with clients before their appointment to see an intake worker (clinician). Young people receiving the intervention felt more involved in treatment decisions with intake workers compared to the comparison group. The project did not measure anxiety and depression symptoms, as the focus was on shared decision making related outcomes; however, it was conducted in a youth mental health service where the majority of clients present with anxiety and/or depression ( headspace ( 24 )). Overall, the findings support the use of peer support in promoting shared decision-making. While the majority of work in this area has focused upon providing peer work within existing mental health services, an additional challenge is that many young people do not access formal services for their mental health concerns ( 25 ). Given that connections with peers are especially important during this developmental period, formal and informal peer support may represent an alternative avenue for young people to access support. For example, Reavley et al. (2011) ( 4 ) surveyed 275 young people with a mental health disorder in Australia to examine factors related to help-seeking and self-help behaviours. Participants most frequently sought help from family (77% of respondents) and close friends (73%), more so than general practitioners (53%). Peer workers may act as a bridge between, for example, untrained friends, and accessing mental health services. Therefore, peer support is a strong candidate intervention for young people with depression and anxiety, since people in this age group experience high rates of these mental health concerns in particular, and they may be more receptive to seeking help from peers before or during engagement with formal services. The aim of this systematic review was to understand the effectiveness of peer support for youth depression and anxiety (aged 14–24) as either a primary or comorbid mental health complaint, including the contexts in which it works, who it does and does not work for, and how it works. Methods Search strategy and information sources This systematic review involved two search strategies. First, we utilised the Orygen Evidence Finder (OEF) database ( 26 ). The OEF is a repository for all available controlled trials (including randomised and non-randomised), systematic reviews and meta analyses that evaluate prevention and treatment strategies for common mental disorders and related challenges that have their peak onset during adolescence and early adulthood (mean age 12–25). These include depression, anxiety, bipolar disorder, substance use disorder, eating disorders, psychotic disorders, and self-harming behaviours. The OEF is an online database publicly available for basic searching. However, for this review we had access to the backend of the system, which allowed us to construct a detailed and reproducible search strategy focused on peer support related terms. Box 1 lists the search terms applied to title, abstract, keyword, and label fields of each publication record within the OEF. The OEF currently contains studies published between 1980 and 30 June 2020, therefore, we undertook a second search process to retrieve studies published to 30 June 2021. This search strategy was conducted in the Embase, MEDLINE and Psycinfo databases (full search strategy in Supplementary File 1). Finally, we conducted backward and forward reference searches through September 2021. #1 [peer*] #2 [consumer OR patient OR service user OR survivor OR client] #3 [operat* OR led OR run OR deliver* OR managed OR support* OR conducted OR assisted] #4 [advoca*OR helper OR mentor OR leader OR counsel* OR educator OR aide OR consultant OR specialist OR train* OR advisor OR facilitat* OR provide*] #5 #2 AND #3 #6 #2 AND #4 #7 #1 OR #5 OR 6 Box 1: Peer support search terms Eligibility criteria We included studies that met the following inclusion criteria: Mean age of participants between 14–24 years; A controlled trial (either randomised or non-randomised); The intervention involved provision of peer support by someone with lived experience of mental health challenges; Reports at least one outcome measure related to depression or anxiety; Full text available in English. Study selection Covidence was used to manage screening ( 27 ); after removing duplicates, two reviewers (SC, EB) independently screened all titles/abstracts and resulting full texts, with disagreements resolved by a third reviewer (MBS). Data extraction Data were extracted from eligible studies into a standardised template covering intervention details, attributes of peer workers, and outcomes measured. A narrative summary of the findings was used to present the data outlined in the data extraction table. Studies were assessed for quality using the Critical Appraisal Skills Programme (CASP; ( 28 )). Registration Time constraints prohibited us from registering our protocol. We have nonetheless ensured reporting is in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement ( 29 ). Lived experience involvement and expert interviews An experienced youth peer worker contributed to the initial proposal, but was unable to work on the review. An international steering group of youth peer workers and young people who have received peer support work was established and convened by a lived experience expert (RM). These consisted of 10 members aged 18–24, from four countries, including Australia ( 4 ), Canada ( 4 ), Ireland ( 1 ), and Singapore ( 1 ). The groups met for two hours fortnightly for the duration of the project. A summary of the contributions from the steering group is provided in Supplementary File 2. Additionally, interviews were conducted with nine experts from eight countries, including Australia, Brazil, Canada, India, Kenya, Nigeria, the United States, and Zambia. A summary of the contributions from expert interviews is provided in Supplementary File 3. Results Search results The searches retrieved 1,500 papers in total (see Fig. 1 for PRISMA flow diagram; ( 29 )). Following removal of 94 duplicates, 1,406 papers were screened for eligibility. Of these, 1,226 were excluded following title and abstract screening, with a further 172 papers excluded after full text screening. Reasons for exclusion are reported in Fig. 1. In total, eight trials met inclusion criteria. Study characteristics Table 2 shows the characteristics of all eight studies, including sample, peer worker, and intervention characteristics. Of the eight studies identified, three were undertaken in North America, two in Oceania, and one each in Asia, Europe, and South America. Only one trial tested an intervention designed for anxiety and depression. The rest were designed for young people at risk of eating disorders or body image concerns (n = 4); any mental illness (n = 1), alcohol and drug misuse (n = 1), and first episode psychosis (n = 1). All eight studies RCTs, including 1,885 participants. An overview of trial results is presented in Table 3 and a full list of outcomes is listed in Supplementary File 4. Table 2 Summary of study characteristic of included trials, including details of peer worker/s Article Country N; gender Mean Age (SD) Sample Intervention/s Detail Control Peer-Worker Requirements Training Depression & Anxiety Ellis et al. (2011) Australia 39; 77% female, 23% male 19.67 (1.66) University Students experiencing low-to-moderate depression & anxiety 3 x 1-hour sessions over 3 weeks working through the content of the MoodGarden website: a. Tools for self-management b. Bulletins on lifestyle management c. Discussions on effective treatments d. Messageboard for peer-based support e. Blogs and Charts 1. MoodGym Five modules of online CBT: a. Introduction to CBT b. Reducing dysfunctional thinking c. Overcoming negative feelings d. Identifying stress and relaxation Problem-solving strategies and enhancing relationships Control: No intervention Lived experience with a mood disorder Not reported Mulfinger et al. (2018) Germany 98; 69% female, non-binary N/A 15.75 (1.15) Inpatients and outpatients with Anxiety and/or Depression 3 x 2-hour sessions weekly over 3 weeks of Honest, Open, Proud (HOP): Themes: a. Challenging beliefs or self-stigma b. Pros & cons of disclosure c. The right person d. Telling one's story e. Role of solidarity and peer support Workbooks contained vignettes, first-person accounts, worksheets, tables and role-plays. 1 young expert and 1 young peer worker TAU Young adult peer with lived experience of Mental Illness Peer facilitators were trained by researchers and conducted a practice session. First Episode Psychosis Alvarez-Jimenez et al. (2021) Australia 170; 47.1% female, 52.9% male 20.91 (2.88) Young people in recovery of First Episode Psychosis, exiting early intervention service Mean Number of Individual posts and/or comments = 21.49 (SD = 41.71) over 18 months (Mean = 8.15 (SD = 5.65)) of Online Social Network: a. Icebreakers b. user-generated threads c. content related to mental health d. content of general interest Vocational training: a. Ask the expert b. individualized online vocational support Online Therapy w/ health professional: a. Online pathways – distinct themes on recovery b. Online Steps - interactive therapy modules Control: TAU Peer workers had lived experience in mental illness. Not Reported Prevention in Eating Disorders Becker et al. (2010) USA 102; 100% female 18.73 (0.72) University students (Freshman or Sophomore) 2 x 2-hour sessions over 2 weeks of Cognitive Dissonance: a. Group Discussions on the thin ideal b. Group Brainstorming on cost on the thin ideal c. Homework body appreciation d. Role-plays on resisting the thin ideal e. Shared lived experiences from peer-leaders and peers in the sessions. 1. Media Advocacy: a. Watch Videos b. Group Discussions of thin ideal c. Group Brainstorming cost on the thin ideal d. Food & exercise diaries Peer-leaders with past participation in the program and a member or the sorority 4.5 hours experiential training sessions. Peer-leaders trained in teams (3–4 peer-leaders at a time). Ciao et al. (2021) USA Trial 1 N = 98; female 80% male 14% non-binary 6% Trial 2 N = 141; 80% female 15% male 5% non-binary Trial 1 20.39 (4.12) Trial 2 19.66 (2.53) University students interested in a body acceptance program 2 x 2-hour group sessions over 2 weeks of the ‘EVERYbody Project’ involving 4–9 participants a. Group Discussions b. Role-Plays c. Group Activities Trial 1: 1 x Expert-leader & 2 peer-leaders Trial 2: 3–4 x peer-leaders Trial 1: Control: No intervention Trial 2: Video Intervention a. Watch Videos b. Reflective Writing Peer-leaders with past participation in the female program Training followed protocol used in the peer-led ‘Body Project’ Trial 1 2 days of training (16 hours). Trial 2 2 days of training (16 hours) with discussion on group facilitation skills and role plays on difficult diverse situations. Kilpela et al. (2016) USA 180; 62% female, 38% male 19.9 (1.2) University students 2 x 2-hour sessions over 2 weeks of ‘Body Project’ a. Group Discussions on the thin ideal contrasting healthy ideal, the origin of the thin-ideal, past pressures b. Group Brainstorming on cost on the thin ideal and combating the thin-ideal c. Homework body appreciation, writing to a young person, challenging own behaviour d. Role-plays on resisting the thin ideal e. Shared lived experiences from peer-leaders and peers in the sessions. Control: Waitlist Peer-leaders with past participation in the program Trainer to Trainer method: Experience peer-leaders in the program trained new peer-leaders over two-days Resendel et al. (2021) Brazil 74; 100% female 20.5 (2.02) University students 4 x 60-minute sessions over 4 weeks of ‘Body Project’ led by two peer-leaders a. Group discussions on the thin-ideal, body appreciation/concerns b. Group brainstorming on the cost of the thin-ideal c. Homework sessions on body appreciation d. Role-plays on resisting the thin-ideal e. Engaged in further body activism Control: No intervention Have experience in Intuitive Eating and past body image concerns and currently a university student References the Body Project website: Therefore, training on the concept and rationale of the body project, in group discussions and role plays, using the manual for guidance. Possibly some practice runs with feedback from supervisors. Prevention in Substance Use German et al. (2012) Thailand 983; 27.3% female 72.7% male Median 19 Used Meth-amphetamine & engaged in sex at least 3 times in the last 3 months, at a Research Community Centre 7 x 1.5-2.5hr group session twice weekly over 1 month of ‘Peer Education’, in groups of 8–12 participants: a. Drug use on individuals b. Drug use and Social influences c. Drug use and Sex d. Drug use and Risk Behaviours e. Family and Community f. Community Project g. Review and Graduation 2 boosters (3 & 6-month mark). 7 x 1.5-2.5hr group session twice weekly over 1 month of ‘Life Skills’, in groups of 8–12 participants: a. Understanding Life b. Decision Making Skills and Old Friends/New Friends c. Danger of Drug Use d. Sexually Infectious Diseases e. How Important is Stress? f. Emotion Management and Life Goals g. Envelope of Goodness and Graduation Network groups for participants in both Peer Education and Life Skills received no intervention Early 20s, participated in an earlier study as part of the ethnography team Researchers trained peer facilitators in a 1 week long intensive training session on building a prosocial role and to increase positive communication interactions with peers. Table 3 Summary results of anxiety and depression outcomes of included trials Ellis et al. (2011) Mulfinger et al. (2018) Alvarez-Jimenez et al. (2021) Becker et al. (2010) Ciao et al. (2021) Kipela et al. (2016) Resende et al. (2021) German et al. (2012) Measures Anxiety and Depression (DASS-21); Depression (CESDS) Depression (CDSS) Negative affect (PANAS-X) Negative Affect (PANAS) Negative Affect (PANAS) Negative Affect (PANAS-B) Depression (CESD) Groups Online Peer Support (n = 13) Online CBT (n = 13) Controls (n = 13) HOP (n = 49) Control (TAU; n = 49) Horyzons + TAU (n = 84) Control (TAU; n = 86) Cognitive Dissonance (n = 53) Control (Media Advocacy; n = 49) Trial 1: Everybody Project (w/ expert - and peer-leaders; n = 48) Control (Waitlist; n = 50) Trial 2: Everybody Project (w/ peer-leaders only; n = 65) Control (Video Intervention; n = 76) Mixed-Gender (n = 77, Female-Only (n = 65) Control (waitlist; n = 38) Body Project (n = 38) Control (n = 36) Peer Education (n = 209) Control (Network Peer Education; n = 286) Life Skills (n = 206) Control (Network Life Skills; n = 282) Anxiety and Depression Results Anxiety Y*; online CBT, d = 0.99, p = .03, and online peer support, d = 0.95, p = .01, compared to controls. Depression ns ns/ Y* FU6W; HOP, d = 0.72, p < .001) compared to controls ns Y* Intervention: post-intervention mean difference = − 4.5251, SE = 0.7279; p < 0.0001), compared to baseline. Control: ns Negative Affect Y* Intervention: postintervention, d = 0.51, p < .05; 8 weeks d = 0.25, p < .05; 8 months d = 0.35, p <. 05; 14 months d = 0.48, p < .05, compared to baseline. Control: postintervention, ns; 8 weeks, ns; 8 months d = 0.58, p < .05; 14 months d = 0.34, p < .05, compared to baseline. Y* Trial 1 EVERYbody (w/ expert - and peer-leaders): postintervention d = 0.56, p < .05; 1-month d = 0.42, p < .05, compared to controls; group x time interaction ( b = − 0.03, t = − 4.45, p < .0001) Trial 2 EVERYbody (w/ peer-leaders only): postintervention d = 0.01, p < .05; 1-month d = 0.10, p < .05 compared to controls; group x time interaction, ns. Y* a Males Intervention: Males in Mixed Gender group: postintervention, d = 0.40, p = 0.0080; 2-month ns; 6-month ns, compared to controls. Females in Mixed Gender group: ns. Females Intervention: Female Only group: ns. ns/Y* b FU24W Intervention: d = 0.60 p < .05) compared to controls. Participant Feedback Online peer support compared to online CBT: • More helpful, • More enjoyable • Equally recommended • One-third reported they would continue using online peer support • Two-thirds reported they would continue using online CBT – possibly because the online CBT group were still feeling more anxious than the online peer-support group. • Peer-leader was viewed as an inspiring role-model • Enjoyed learning about their real-life experiences. • Relief to talk about disclosure in a safe space. • facilitated openness, trust, and respect within the group interactions • Some materials were deemed too theoretical, demanding, and hard to concentrate on or too detailed. • Some participants had positive experiences of social connection on Horyzons. • Others did not due to social anxiety, paranoia and confusion within the social network of Horyzons. • Participants preferred the Cognitive Dissonance intervention over the Control intervention. • Both interventions were deemed useful • Suggested the Control intervention may be a good follow up or refresher intervention. • Experts were able to address diverse body images (various gender-, sexual-, and racial-identities) better than peer-leaders. • Peer-leaders lacked lived experience in all diverse body images, which may have hindered them in connecting with all the participants. • Adding males to the Body Project created a Mixed Gender Group, which established a warmer collaborative (versus activating) vibe, • Normally the Body Project creates an angry vibe against the thin-ideal through the historical struggle women have had against the thin-ideal. • This warmer vide was carried over to the Female Only Group, which may explain a lack of effects among females. Not reported The research site (known as “House of Friends”): • Allowed participants to gather and socialise informally with each other. • Was a safe place, as there was no social stigma or fear of being arrested, which was common for participants in the general community. Note : Y*(bolded) = significant result, ns = non-significant, FU = Follow-up, (number)W/M = number of weeks or months, Note: DASS-21 = Depression, Anxiety and Stress Scale, CESDS = Center for Epidemiologic Studies Depression Scale, CDSS =- Calgary Depression Scale for Schizophrenia, PANSS = Positive and Negative Syndrome Scale, PANASX = Positive and Negative Affect Schedule – Revised, PANAS = Positive and Negative Affect Schedule, PANAS-B = Positive and Negative Affect Schedule, CESD = Centers for Epidemiological Studies Depression Scale. a Kipela et al. (2016) found negative affect only decreased with the males in their mixed-gender group, not with the females in the mixed-gender group or with the female only group. b Resende et al. (2021) found negative affect only decreased at the 24-week follow-up, not at post-intervention, or four weeks follow-up. Depression and anxiety The first study on depression and anxiety was undertaken in Australia with University students, experiencing low-to-moderate depression & anxiety ( 30 ). Students were randomised into one of two experimental groups or a no-intervention control group. The first group engaged in online CBT via ‘MoodGym’ and the second group engaged in an online peer support group via ‘MoodGarden’ (see Table 2 for intervention characteristics). ‘MoodGarden’ involved access to the established non-profit website run by volunteers with lived experience of a mood disorder. Peer workers mediated the message board that the participants posted on. Compared to the control group, post-intervention measures showed that the online CBT and online peer support significantly reduced anxiety symptoms (see Table 3 ). However, neither intervention affected depression symptoms. ‘MoodGarden’ participants reported higher perceived online social support compared to the ‘MoodGym’ and control groups (see Supplementary File 4). Any mental illness The second study ( 31 ) was undertaken in Germany with teenagers (mean age 16) experiencing depression and anxiety, mainly in inpatient settings. They compared an intervention known as Honest, Open, Proud (HOP) to a treatment as usual (TAU) control group (see Table 2 for intervention details). This group program was co-facilitated by a peer and aimed to support individuals in their decisions to disclose their mental illness and therefore reduce the impact of stigma for adolescents. Depressive symptoms were measured as secondary outcomes and showed no reduction post-intervention; however, at six-week follow-up, depressive symptoms had significantly reduced (see Table 3 ). There was a significant difference between groups in favour of the intervention group for the primary endpoints (reduction in stigma stress post intervention and improvement in quality of life at follow up). Other positive effects found that may overlap with peer support mechanisms included help-seeking intentions (family/friends, professionals), stage of recovery, and empowerment (self-esteem, optimism; see Supplementary File 4). No effect was found for social withdrawal or hopelessness. Attrition rates between post-intervention and follow-up were the same for both groups (n = 11); reasons included being uncontactable or refusing to complete follow-up. This study was the only included study to conduct a cost-effectiveness analysis aimed at calculating value for money of delivery of the intervention. HOP’s total costs, including, for example, the training and employment of peers and professionals and overhead costs, were calculated and compared to British annual costs per young person (aged 5 to 15) where the National Institute for Health and Care Excellence (NICE) uses a cost-effectiveness threshold of £20,000–£30,000/QALY ( 32 ). Based on the utility gains (0.044), HOPS was deemed to be a cost-effective intervention, even if those gains only lasted for two months (at a cost of €20,533/QALY), but more so if the gains continued at six months (€6,969/QALY). First Episode Psychosis One study that assessed depression in young people with a recent onset psychotic disorder was identified ( 33 ). The intervention ‘Horyzons’ used the ‘Moderated Online Social Therapy’ model, which integrates interactive online therapy, peer-to-peer online social networking, peer moderation, and expert support (see Table 2 ). While the intervention was shown to improve vocational functioning and reduce hospital emergency service use compared to TAU, no effect was found for depression symptoms ( p = .42) or any peer-support related constructs (e.g. loneliness; see Supplementary File 4). Eating disorders Four studies tested slightly different versions of a lived-experience peer-worker led intervention known as the Body Project Collaborative (see Table 2 for intervention details), which aims to prevent eating disorders and body dissatisfaction. All studies were successful in reducing body image concerns and eating disorder risk. All involved University students, three in the USA ( 34 – 36 ), and one in Brazil ( 37 ). All utilised the Positive and Negative Affect Schedule, with the effect of these interventions on negative affect varying across trials. Table 3 shows two ( 34 , 35 ) found significant reduction of negative affect over time. Resende and colleagues ( 37 ) found an increase in self-esteem at post-invention and 24 weeks (see Supplementary File 4). However, they only found a significant reduction in negative affect at 24 weeks. Kilpela, Blomquist ( 36 ) reported a significant reduction of negative affect only in male participants. Overall peer-led interventions across all studies had significantly better outcomes compared to control groups. Substance use The final trial targeted young methamphetamine users in Thailand ( 38 ). Secondary analysis of the trial demonstrated a significant effect for depression symptoms; however, this was not the primary aim of the trial. The intervention was a ‘Peer Education’ group that aimed to teach participants to reduce their methamphetamine use and sexual risk behaviours as well as how to communicate learnings from the group with their methamphetamine using peers or sexual partners. The authors hypothesised the intervention had a significant impact on depression (see Table 3 ) due to the intervention encouraged participants to build a prosocial role and increase positive communication with peers and family members. The emphasis on social relationships and contributing to the community may have affected feelings of isolation and stigma, particularly within a collectivist culture such as Thailand. Quality of studies Supplementary File 5 shows the overall quality of the studies was good using the Critical Appraisal Skills Programme. Importantly, six studies were partially or fully unclear on blinding procedures. Four studies did not account for missing data and four studies did not conduct a priori power analyses. No measures of fidelity were used. Discussion Overall findings In this review, we aimed to identify and describe studies of peer support for young people to improve symptoms of depression or anxiety. We sought to investigate in which ways, in which contexts, and for whom, peer support appears to work or not work. Despite there being a range of controlled trials testing peer support interventions for adults with mental health challenges such as anxiety and depression ( 39 – 41 ), very few have been conducted in young people. We were only able to identify two trials specifically targeting anxiety or depression, and there were limitations across studies that we will now discuss. In total, six studies were conducted in high income countries and two in low- and middle-income countries. The most common setting was Universities (5 studies), with only two mental health service settings and one research community centre. Aside from the considerable lack of geographical diversity, the settings also limit our knowledge of the context in which peer support might work, given that only a small proportion of young people attend University or mental health services. Many studies in a broader range of settings were excluded because the peer worker role did not require lived experience. The variability of this requirement, which is mirrored in research with adults ( 12 – 14 ), is just one factor that is indicative of the generally heterogeneous array of definitions of peer support, in terms of the setting, intervention, and peer. We note that the core values of peer support are based on lived experience, which is why this was deemed an essential criterion for inclusion. In what contexts does peer support work? Importantly, two studies ( 30 , 33 ) successfully and safely tested online peer support interventions. Understanding how peer support can be delivered remotely is important in the context of the current COVID-19 global pandemic, and complements work done on peer-to-peer support ( 42 ). As young people globally grapple with the increase in social isolation, uncertainty about the future, and other experiences that are related to poorer mental health, having sufficient workforce supply to serve the demand of those seeking help is essential. Although it should not be seen as ‘cheap labour’, with the right support structures in place ( 23 ), peer workers are able to be trained more readily than other professions. One study specifically assessed and reported no adverse effects ( 34 ); participant feedback from the other studies were generally good (see Table 3 ) and successful interventions were found to be acceptable, suitable, and cost-effective, in line with adult reviews ( 12 , 14 , 17 , 39 ). It is also easier to ensure diversity in the workforce through peer support, as the barriers to formal education pathways that exist for many minority groups are less prominent in peer work. As our steering group members pointed out, better representation from minority groups in the workforce is more likely to result in culturally safer environments. For whom does peer support work? In terms of understanding who peer support may or may not work for, we were unable to answer this. Only two studies focused specifically on depression and anxiety, with the rest focused on relapse prevention after first episode psychosis, substance use disorders and four focused on the prevention of eating disorders. In line with adult literature, depression related measures were more commonly used and anxiety related measures were largely absent ( 39 – 41 ). Unlike the adult peer support literature as reviewed by King, Simmons ( 12 ), the studies we found in youth settings did not aim to measure the impact of peer support, any overlapping measures such as hope and empowerment were tied back to their initial study aims. Further, the mean age of participants in all but one trial fell in the young adult range (19–21 years). Peer support has been widely tested in educational settings with children and adolescents; however, peers are not required to have lived experience, meaning they don’t contribute to our understanding of lived experience as an active ingredient or align with the core principles of peer support in a mental health context. Developing and testing lived experience-based peer support in younger groups requires careful consideration of what age one might expect a peer worker to be ( 43 , 44 ). While having a peer worker be as close in age as possible, it also makes good sense to have slightly older peer workers who have experienced both relevant mental health challenges and some experiences of treatment and recovery. Overall, it is not yet discernible who peer support does and does not work for. Why might peer support work? Specific mechanisms of action for peer support in youth depression and anxiety are yet to be proposed and tested. The lack of clarity in the evidence we did find (e.g. definition of a peer worker, what the intervention is, and what peer support values or principles were adhered to) makes it even more difficult to understand mechanisms. As a starting point to address this gap, we drew on the findings of this review and previous literature from adults ( 9 , 12 , 13 , 15 , 45 , 46 ), together with input from the steering groups and expert interviews that informed this review, to propose a preliminary model for the mechanisms of action regarding peer support for youth anxiety and depression (see Fig. 2). However, empirical work that tests this proposed model is required. Other critical gaps in the literature include exploring the best ways to test the ‘effectiveness’ of peer support interventions in this area. When our systematic review failed to identify many studies, we searched for existing youth peer support programs and checked for any related research or evaluation. We found a number of programs operating in a range of countries, although we did not find any associated evaluation, suggesting a lost opportunity to properly understand how these programs are helping young people who experience depression and anxiety. In contrast, the steering groups responded optimistically, suggesting there is a wealth of knowledge to draw on from the programs run by groups who are out helping young people on the ground. Harnessing this knowledge will require careful consideration of what types of research designs and methodologies are appropriate for peer support ( 47 ). Much of mental health research is based on a medical/clinical model that focuses on individual deficits ( 48 ). This is at odds with both the theoretical underpinnings of peer support models (e.g. Intentional Peer Support) ( 47 ) and also the collectivist nature of many cultures worldwide, as recognised by one of the trials identified in our review ( 38 ). Focusing on the programs already operating, mainly in high income countries, is essential in order to capture the lessons already learned about how people with lived experience of anxiety and depression can help their peers. Understanding how peer support programs operate effectively in low resource settings and in varying cultural contexts, yet retain relevant core values of peer support, is equally as important. Furthermore, peer support has also been associated with engaging in generative actions such as helping others, changing organisations and systems, and sharing personal stories ( 49 ), which can lead to a range of psychosocial benefits on both the individual and relational interpersonal levels ( 7 , 15 ). Regardless of the research setting and cultural context, this review highlighted a number of areas requiring clarity (see Supplementary File 6). First of all, role-specific definitions of peer and lived experience are vital, including relevancy of age, characteristics and type of lived experience (e.g. experience of mental health challenges, receipt of treatment, and recovery). Secondly, detailed descriptions of peer support interventions are required that explain: 1) the theoretical underpinning, core values and principles of the intervention; 2) how fidelity to is assessed; 3) the nature of the role and how the peer worker was supported to adhere to these values and principles in their role (i.e. training and supervision). Further, given that a number of barriers to implementing peer work in practice have been identified in adult settings (e.g. ( 10 )) and are likely exacerbated in youth settings ( 43 , 44 ), future research should use designs incorporating implementation science methodologies from the outset. There are also unresolved issues beyond the scope of research, such as what happens to youth peer workers when they age out of the age-related role requirements. All of these elements were generally lacking in the literature we reviewed, but are critical for moving the field forward. Lastly, only two of the studies used a co-design approach to intervention development. These interventions were both digital in nature, which is unsurprising given that user-centred design methodologies are common in the development of digital solutions. Involving young people with lived experience of anxiety and depression in all aspects of peer support intervention design and testing will improve the quality and significance of such endeavours ( 50 ). Similarly, involvement from experienced youth peer workers will also help ensure interventions are appropriate, feasible, and meaningful. Drawing on the existing knowledge held by the youth peer workforce and young people who have accessed peer support interventions is the most promising avenue for determining the ways in which peer support is an active ingredient for youth depression and anxiety. List of abbreviations CASP Critical Appraisal Skills Programme CBT Cognitive Behavioural Therapy HOP Honest, Open, Proud NICE The National Institute for Health and Care Excellence OEF Orygen Evidence Finder PRISMA Preferred Reporting Items for Systematic Reviews and Meta-Analyses QALY Quality adjusted life years RCT Randomised controlled trial SES Socio-economic status TAU Treatment as usual USA United States of America Declarations Ethics approval and consent to participate No research participants were involved in this study. We worked with an international steering group of young adult peer workers and/or young adults who had received peer work. They contributed their expertise as advisors to the review, and provided consent to do so by completing an expression of interest form. They were not involved as research participants. We also sought advice from peer support experts, who were consulted to improve the quality of the review. In line with our institutional requirements, we did not have to seek ethical approval to involve either group as advisors. Consent for publication Not applicable. Availability of data and materials The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests The authors declare that they have no competing interests. Funding This work was funded by a Wellcome Trust Mental Health Priority Area 'Active Ingredients' 2021 commission awarded to MBS at Orygen and The University of Melbourne. Authors’ contributions MBS and EB designed the review with assistance from AB. AB and MBS designed the search strategy and AB performed database searches. MBS, SC, AB and EB undertook screening. RM coordinated the steering group meetings. All authors contributed to the drafting of the manuscript, led by MBS. All authors read and approved the final version of the manuscript. Acknowledgements We would like to acknowledge additional technical support from Sarah Bostock, Stefanie De Silva, Alicia Randell, Samantha Cooke, Kelly Allott, Nicola Acevedo, steering group members (Rafi Armanto, Nawira Baig Bte Istrar Baig, Diana Dimitrov, Aisling Dillon, Mahalia Dixon, Cassandra Jankovic, Kiera Jean Lowe, Lauren Luliani, Niamh Petrie, and one anonymous member), and experts who participated in interviews (Mikaela Basile, Michelle Blanchard, Naeem Dalal, Mardi Daley, Raffael Masuda, Janet Walker, and three anonymous interviewees). References Kessler RC, Amminger GP, Aguilar-Gaxiola S, Alonso J, Lee S, Ustun TB. Age of onset of mental disorders: a review of recent literature. Curr Opin Psychiatry. 2007;20(4):359–64. Young Minds Matter. The Mental Health of Children and Adolescents: Report on the Second Australian Child and Adolescent Survey of Mental Health and Wellbeing. Australian Government Department of Health,; 2013-14. 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Effectiveness of peer support intervention on perinatal depression: A systematic review and meta-analysis. J Affect Disord. 2020;276:788–96. Pfeiffer PN, Heisler M, Piette JD, Rogers MA, Valenstein M. Efficacy of peer support interventions for depression: a meta-analysis. Gen Hosp Psychiatry. 2011;33(1):29–36. Suresh R, Alam A, Karkossa Z. Using Peer Support to Strengthen Mental Health During the COVID-19 Pandemic: A Review. Frontiers in Psychiatry. 2021;12(1119). Fava N, O'Bree B, Randall R, Kennedy H, Olsen J, Matenson E, et al. Youth Peer Work: Building a Strong and Supported Youth Peer Workforce. In: Meagher J, Stratford A, Jackson F, Jayakody E, Fong T, editors. Peer Work in Australia: A New Future for Mental Health. g. a. h ed. Sydney: RichmondPRA and Mind Australia.; 2018. p. d. Fava N, Simmons MB, Anderson R, Zbukvic I, Baker D. Side by side: supporting youth peer work in mental health services. Melbourne: Orygen 2020. Burke EM, Pyle M, Machin K, Morrison AP. 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Supplementary Files SupplementaryFile1.pdf Supplementary File 1: Full search strategies for Embase, MEDLINE and PyscInfo databases Supplementaryfile2.pdf Supplementary File 2: Overview of input from steering groups SupplementaryFile3.docx Supplementary File 3: Notes from expert interviews Supplementaryfile4.pdf Supplementary File 4: Additional outcomes reported by included trials SupplementaryFile5.pdf Supplementary File 5: Critical Appraisal Skills Programme ratings Supplementaryfile6.pdf Supplementary File 6: Research gaps highlighted in review, informed by input from expert interviews and steering group members Cite Share Download PDF Status: Published Journal Publication published 24 Mar, 2023 Read the published version in BMC Psychiatry → Version 1 posted Editorial decision: Major revision 30 Jun, 2022 Reviews received at journal 15 Jun, 2022 Reviewers agreed at journal 12 Jun, 2022 Reviewers agreed at journal 23 May, 2022 Reviewers invited by journal 22 May, 2022 Editor assigned by journal 20 May, 2022 Editor invited by journal 17 May, 2022 Submission checks completed at journal 17 May, 2022 First submitted to journal 02 May, 2022 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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interviews\u003c/p\u003e","description":"","filename":"SupplementaryFile3.docx","url":"https://assets-eu.researchsquare.com/files/rs-1617867/v1/555dfe5ebd560a43aa25f0c9.docx"},{"id":21713506,"identity":"77d8083a-7e25-4dbf-9db1-710e7fa10a3e","added_by":"auto","created_at":"2022-05-20 15:19:58","extension":"pdf","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":171780,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary\u0026nbsp;File 4: Additional outcomes reported by included trials\u003c/p\u003e","description":"","filename":"Supplementaryfile4.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1617867/v1/8f314af3a4bf2dc098faaa1e.pdf"},{"id":21712995,"identity":"ae170e11-095c-4e6b-a0c2-8c7081482a56","added_by":"auto","created_at":"2022-05-20 15:14:58","extension":"pdf","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":89703,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary\u0026nbsp;File 5: Critical Appraisal Skills Programme ratings\u003c/p\u003e","description":"","filename":"SupplementaryFile5.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1617867/v1/821e78c259b67d3014d7ab26.pdf"},{"id":21712993,"identity":"9f78445b-5837-461e-a03a-cd58fbd7c0d3","added_by":"auto","created_at":"2022-05-20 15:14:58","extension":"pdf","order_by":6,"title":"","display":"","copyAsset":false,"role":"supplement","size":85471,"visible":true,"origin":"","legend":"\u003cp\u003eSupplementary\u0026nbsp;File 6: Research gaps highlighted in review, informed by input from expert interviews and steering group members\u003c/p\u003e","description":"","filename":"Supplementaryfile6.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1617867/v1/b281a8f6d1f10cb761c70cb1.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The effectiveness of peer support from a person with lived experience of mental health challenges for young people with anxiety and depression: A systematic review","fulltext":[{"header":"Background","content":"\u003cp\u003eDepression and anxiety are prevalent mental health challenges, with onset commonly occurring during adolescence and early adulthood (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). In an Australian survey of young people between 4\u0026ndash;17 years of age, 6.9% had an anxiety disorder and 2.8% had major depressive disorder in the 12 months prior, which was associated with high levels of distress, self-harm, and impacts on schooling (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Twelve-month prevalence continues to increases; for example, in an international survey of 14,000 University students, around 18.5% experienced depression and 16.7% anxiety (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e). While some young people receive help from trained professionals, a large proportion experience barriers to accessing services or do not have their needs fully met by services (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). For those who do seek help, peers play a critical part in the help seeking process for young people, who often turn to friends and family first before accessing formal help (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eThe degree to which informal support from peers, such as friends and acquaintances, is helpful will depend on how capable and willing peers are to provide such support. Attempts have been made to formalise peer support for promoting mental health and wellbeing in educational settings (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). Although peer support can occur across multiple settings, there is a rapidly growing peer workforce in mental health services, especially in high income countries (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Peer workers (also called peer support workers, peer practitioners and other terms) are positioned in mental health services and trained to draw on their lived experience of mental health challenges.\u003c/p\u003e \u003cp\u003eIn contrast to other roles in the mental health system, the peer relationship is uniquely characterised by shared experience; the value of expertise through experience rather than clinical education and training; and reciprocity/ mutuality, whereby both individuals explicitly learn and benefit from the relationship (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). Peers are responsible for establishing and continually negotiating the \u0026lsquo;rules\u0026rsquo; and power structures of the relationship, unlike a clinician-patient relationship (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Five common mechanisms have been identified across various models of peer support: \u003cem\u003elived experience\u003c/em\u003e; \u003cem\u003elove labour\u003c/em\u003e, which refers to assurance of the emotional safety and wellbeing of peers; \u003cem\u003eliminality\u003c/em\u003e of the peer worker, describing their position between identities of \u0026lsquo;patient\u0026rsquo; and \u0026lsquo;clinician\u0026rsquo;; \u003cem\u003estrengths-focussed social and practical support\u003c/em\u003e, and the \u003cem\u003ehelper role\u003c/em\u003e of the peer worker, which can facilitate their own recovery (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eHowever, mental health services are not always favourable settings for peer support. A number of barriers to implementation have been identified, including role confusion (i.e. employers and/or peer workers not knowing what the role is and how it fits within the service), role diffusion (i.e. spending time doing non-peer support tasks), co-optation (i.e. tasks becoming clinical in nature), professional stigma (i.e. negative attitudes from others and lack of credibility), and lack of support (i.e. availability of peer supervision, appropriate training and professional development) (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDespite challenges, several reviews and meta-analyses have assessed the effectiveness of peer support interventions for adults with mental health challenges, finding that client and program characteristics varied widely (\u003cspan additionalcitationids=\"CR13 CR14\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). For example, peer workers delivered a range of services, such as peer education, peer support, mentoring, psychoeducation, and case management, in different settings and mediums (see Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e for examples of peer support). Regardless, peer support interventions appear to be effective at improving hope, empowerment, increasing patient activation and self-efficacy (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). While one review (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e) did not report a significant difference in hope, they suggest this could be attributed to the limited amount of included studies that focused on this, and differences in methodologies and outcome measures.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eDifferent Real-World Models of Peer Support\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eModel\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDescription\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDelivery Methods\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSpecific Model Benefits\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eExample\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOne-on-one\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePeer Support given between two people. Most likely involving a professional third-party to link the two people together.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFace to face, Phone, Online\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTailored for the individual.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1-on-1 Peer Support Appointments (Orygen; \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://oyh.org.au/client-hub/peer-support-team/1-1-peer-support-appointments\u003c/span\u003e\u003cspan address=\"https://oyh.org.au/client-hub/peer-support-team/1-1-peer-support-appointments\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroup peer-to-peer support\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGroups share a lived experience. May be structured and organised, however, no formal facilitator. Can be independent or tied to a larger network.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFace to face, Online\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTailored to the shared lived experience. Can be informal and include social activities.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eGrow (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.grow.org.au/\u003c/span\u003e\u003cspan address=\"https://www.grow.org.au/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePeer-led groups\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePeer-Leaders sharing their lived experience to support and educate others similar to themselves. Can be workshops or structured group peer support often tied to a larger network.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFace to face, Online\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTailored to the shared lived experience, may have educational aspects.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHearing Voices Network (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.hearing-voices.org/\u003c/span\u003e\u003cspan address=\"https://www.hearing-voices.org/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGroups co-facilitated by peer and traditionally qualified expert (e.g. clinician)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOften involves professional health services, where a group of people with a shared lived experience are supported by both an expert and peer. Can be structured and formal.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFace to face, Online\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTailored to both group and individual, may have educational and treatment aspects.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eHeadspace centres (\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://headspace.org.au/headspace-centres/sunshine/youth-peer-support-at-headspace-sunshine/\u003c/span\u003e\u003cspan address=\"https://headspace.org.au/headspace-centres/sunshine/youth-peer-support-at-headspace-sunshine/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOnline peer support\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCan be one on one or group format. May have professional involvement through moderators. Mostly peer-to-peer support through forums.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOnline\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCan be anonymous.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSide by Side (Mind; \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://sidebyside.mind.org.uk/\u003c/span\u003e\u003cspan address=\"https://sidebyside.mind.org.uk/\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eAdapted from: \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.nationalvoices.org.uk/peer-support-hub/peer-support-models-explained\u003c/span\u003e\u003cspan address=\"https://www.nationalvoices.org.uk/peer-support-hub/peer-support-models-explained\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/td\u003e\u003c/tr\u003e \u003ctr\u003e\u003ctd colspan=\"5\"\u003eNB: All models may be provided in either a traditional service (e.g. community mental health service) or peer-led service.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003ePeer support interventions in adult populations generally did not impact quality of life, overall symptom severity, social inclusion (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e), depression and anxiety symptoms (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e), measures of hospitalisation (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e), or service satisfaction (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). Mixed results were reported for several outcomes, including service use (\u003cspan additionalcitationids=\"CR13 CR14\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e) and client ratings of the working relationship (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). However, more recent evidence (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e) has demonstrated a reduction in 12-month rate of readmission to acute care following a self-management program delivered by peer support workers after patients had left the care of mental health crisis teams. The intervention also increased time until first readmission. This recent evidence suggests that peer support may reduce hospitalisations, an important objective outcome for health services worldwide. Trachtenberg (2013) (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e) found that peer support work significantly reduces hospital bed use, with the average financial savings outweighing additional costs of employing peer support workers (benefit:cost ratio of 4.76:1), highlighting the cost-effectiveness of peer support.\u003c/p\u003e \u003cp\u003eWhile these reviews focused on services for individuals with \u0026lsquo;severe mental illnesses\u0026rsquo; (typically psychoses, bipolar disorder, severe depression), several meta-analyses have assessed peer support specifically for \u0026lsquo;common\u0026rsquo; mental health disorders (e.g., depression and anxiety). Pfeiffer, Heisler (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e) included studies comparing peer support versus treatment as usual (TAU) or group cognitive behavioural therapy (CBT) for adults experiencing depression. The peer support group demonstrated a greater reduction in depression scores compared to TAU, but not significantly different to CBT, suggesting possible efficacy at the level of established treatments (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e). However, there was wide variability in patient populations, with many studies focusing on subpopulations, such as perinatal mothers. Similarly, Huang, Yan (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e) reviewed randomised controlled trials (RCTs) of women with perinatal depression who received either peer support or TAU. For those who received peer support, depression scores were lower than controls, most participants reported intervention satisfaction, and it was cost-effective. Likewise, Field, Diego (\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e) reported that for women with prenatal depression who received group peer support or group interpersonal psychotherapy, both groups demonstrated significantly lower depression symptoms and cortisol levels (with a greater decrease in cortisol for the peer support group), despite the former group having a lower socio-economic status (SES), higher baseline depression scores, and shorter group sessions. Altogether, the available evidence suggests that peer work is a safe, effective, flexible and cost-effective intervention for adults, which promotes hope, empowerment, patient activation and self-efficacy, and reduces hospitalisations.\u003c/p\u003e \u003cp\u003ePrevious work has focused foremost on adult populations, and there is a paucity of literature regarding young people. Using both peer-reviewed and grey literature, Gopalan and colleagues (2017) (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e) undertook a United States-specific scoping review of youth peer support services and research for young people under 25 years old with emotional or behavioural problems. In total, 43 articles were identified (only three were randomised controlled trials), with a range of different peer support models, including differences in the program goals, the degree to which peer workers were involved, and the roles they undertook. There was also variation within the peer worker roles, including core competencies, training and supervision received by peer workers. Outside of the USA, the CHOICE project (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e) in Australia, studied the impact of youth peer workers supporting consumers (aged 16 to 25 years) to take part in shared decision making regarding their mental health treatment. Peer workers used a co-designed shared decision-making tool with clients before their appointment to see an intake worker (clinician). Young people receiving the intervention felt more involved in treatment decisions with intake workers compared to the comparison group. The project did not measure anxiety and depression symptoms, as the focus was on shared decision making related outcomes; however, it was conducted in a youth mental health service where the majority of clients present with anxiety and/or depression (\u003cem\u003eheadspace\u003c/em\u003e (\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e)). Overall, the findings support the use of peer support in promoting shared decision-making.\u003c/p\u003e \u003cp\u003eWhile the majority of work in this area has focused upon providing peer work within existing mental health services, an additional challenge is that many young people do not access formal services for their mental health concerns (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e). Given that connections with peers are especially important during this developmental period, formal and informal peer support may represent an alternative avenue for young people to access support. For example, Reavley et al. (2011) (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e) surveyed 275 young people with a mental health disorder in Australia to examine factors related to help-seeking and self-help behaviours. Participants most frequently sought help from family (77% of respondents) and close friends (73%), more so than general practitioners (53%). Peer workers may act as a bridge between, for example, untrained friends, and accessing mental health services.\u003c/p\u003e \u003cp\u003eTherefore, peer support is a strong candidate intervention for young people with depression and anxiety, since people in this age group experience high rates of these mental health concerns in particular, and they may be more receptive to seeking help from peers before or during engagement with formal services. The aim of this systematic review was to understand the effectiveness of peer support for youth depression and anxiety (aged 14\u0026ndash;24) as either a primary or comorbid mental health complaint, including the contexts in which it works, who it does and does not work for, and how it works.\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv class=\"Section2\" id=\"Sec3\"\u003e\n \u003ch2\u003eSearch strategy and information sources\u003c/h2\u003e\n \u003cp\u003eThis systematic review involved two search strategies. First, we utilised the Orygen Evidence Finder (OEF) database (\u003cspan class=\"CitationRef\"\u003e26\u003c/span\u003e). The OEF is a repository for all available controlled trials (including randomised and non-randomised), systematic reviews and meta analyses that evaluate prevention and treatment strategies for common mental disorders and related challenges that have their peak onset during adolescence and early adulthood (mean age 12\u0026ndash;25). These include depression, anxiety, bipolar disorder, substance use disorder, eating disorders, psychotic disorders, and self-harming behaviours. The OEF is an online database publicly available for basic searching. However, for this review we had access to the backend of the system, which allowed us to construct a detailed and reproducible search strategy focused on peer support related terms. Box 1 lists the search terms applied to title, abstract, keyword, and label fields of each publication record within the OEF. The OEF currently contains studies published between 1980 and 30 June 2020, therefore, we undertook a second search process to retrieve studies published to 30 June 2021. This search strategy was conducted in the Embase, MEDLINE and Psycinfo databases (full search strategy in Supplementary File 1). Finally, we conducted backward and forward reference searches through September 2021.\u003c/p\u003e\n \u003ctable border=\"1\" style=\"height: 181px; width: 546px;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 102.656%;\"\u003e\n \u003cp\u003e#1\u0026nbsp; [peer*]\u003c/p\u003e\n \u003cp\u003e#2\u0026nbsp; [consumer OR patient OR service user OR survivor OR client]\u003c/p\u003e\n \u003cp\u003e#3\u0026nbsp; [operat* OR led OR run OR deliver* OR managed OR support* OR conducted OR assisted]\u003c/p\u003e\n \u003cp\u003e#4\u0026nbsp; [advoca*OR helper OR mentor OR leader OR counsel* OR educator OR aide OR consultant OR specialist OR train* OR advisor OR facilitat* OR provide*]\u003c/p\u003e\n \u003cp\u003e#5\u0026nbsp; #2 AND #3\u003c/p\u003e\n \u003cp\u003e#6\u0026nbsp; #2 AND #4\u003c/p\u003e\n \u003cp\u003e#7\u0026nbsp; #1 OR #5 OR 6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003cp\u003e\u003cstrong\u003eBox 1: Peer support search terms\u003c/strong\u003e\u003c/p\u003e\n \u003cdiv class=\"Section3\" id=\"Sec4\"\u003e\u0026nbsp;\u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec8\"\u003e\n \u003ch2\u003eEligibility criteria\u003c/h2\u003e\n \u003cp\u003eWe included studies that met the following inclusion criteria:\u003c/p\u003e\n \u003col\u003e\n \u003cli\u003e\n \u003cp\u003eMean age of participants between 14\u0026ndash;24 years;\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003eA controlled trial (either randomised or non-randomised);\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003eThe intervention involved provision of peer support by someone with lived experience of mental health challenges;\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003eReports at least one outcome measure related to depression or anxiety;\u003c/p\u003e\n \u003c/li\u003e\n \u003cli\u003e\n \u003cp\u003eFull text available in English.\u003c/p\u003e\n \u003c/li\u003e\n \u003c/ol\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec9\"\u003e\n \u003ch2\u003eStudy selection\u003c/h2\u003e\n \u003cp\u003e\u003cem\u003eCovidence\u003c/em\u003e was used to manage screening (\u003cspan class=\"CitationRef\"\u003e27\u003c/span\u003e); after removing duplicates, two reviewers (SC, EB) independently screened all titles/abstracts and resulting full texts, with disagreements resolved by a third reviewer (MBS).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec10\"\u003e\n \u003ch2\u003eData extraction\u003c/h2\u003e\n \u003cp\u003eData were extracted from eligible studies into a standardised template covering intervention details, attributes of peer workers, and outcomes measured. A narrative summary of the findings was used to present the data outlined in the data extraction table. Studies were assessed for quality using the Critical Appraisal Skills Programme (CASP; (\u003cspan class=\"CitationRef\"\u003e28\u003c/span\u003e)).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec11\"\u003e\n \u003ch2\u003eRegistration\u003c/h2\u003e\n \u003cp\u003eTime constraints prohibited us from registering our protocol. We have nonetheless ensured reporting is in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement (\u003cspan class=\"CitationRef\"\u003e29\u003c/span\u003e).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec12\"\u003e\n \u003ch2\u003eLived experience involvement and expert interviews\u003c/h2\u003e\n \u003cp\u003eAn experienced youth peer worker contributed to the initial proposal, but was unable to work on the review. An international steering group of youth peer workers and young people who have received peer support work was established and convened by a lived experience expert (RM). These consisted of 10 members aged 18\u0026ndash;24, from four countries, including Australia (\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e), Canada (\u003cspan class=\"CitationRef\"\u003e4\u003c/span\u003e), Ireland (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e), and Singapore (\u003cspan class=\"CitationRef\"\u003e1\u003c/span\u003e). The groups met for two hours fortnightly for the duration of the project. A summary of the contributions from the steering group is provided in Supplementary File 2. Additionally, interviews were conducted with nine experts from eight countries, including Australia, Brazil, Canada, India, Kenya, Nigeria, the United States, and Zambia. A summary of the contributions from expert interviews is provided in Supplementary File 3.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Results","content":"\u003cdiv class=\"Section2\" id=\"Sec14\"\u003e\n \u003ch2\u003eSearch results\u003c/h2\u003e\n \u003cp\u003eThe searches retrieved 1,500 papers in total (see Fig.\u0026nbsp;1 for PRISMA flow diagram; (\u003cspan class=\"CitationRef\"\u003e29\u003c/span\u003e)). Following removal of 94 duplicates, 1,406 papers were screened for eligibility. Of these, 1,226 were excluded following title and abstract screening, with a further 172 papers excluded after full text screening. Reasons for exclusion are reported in Fig.\u0026nbsp;1. In total, eight trials met inclusion criteria.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec15\"\u003e\n \u003ch2\u003eStudy characteristics\u003c/h2\u003e\n \u003cp\u003eTable\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e shows the characteristics of all eight studies, including sample, peer worker, and intervention characteristics. Of the eight studies identified, three were undertaken in North America, two in Oceania, and one each in Asia, Europe, and South America. Only one trial tested an intervention designed for anxiety and depression. The rest were designed for young people at risk of eating disorders or body image concerns (n\u0026thinsp;=\u0026thinsp;4); any mental illness (n\u0026thinsp;=\u0026thinsp;1), alcohol and drug misuse (n\u0026thinsp;=\u0026thinsp;1), and first episode psychosis (n\u0026thinsp;=\u0026thinsp;1). All eight studies RCTs, including 1,885 participants. An overview of trial results is presented in Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e and a full list of outcomes is listed in Supplementary File 4.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable border=\"1\" id=\"Tab2\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eSummary of study characteristic of included trials, including details of peer worker/s\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eArticle\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCountry\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eN; gender\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMean Age (SD)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSample\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eIntervention/s Detail\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eControl\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\" colspan=\"2\"\u003e\n \u003cp\u003ePeer-Worker\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eRequirements\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eTraining\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"9\"\u003e\n \u003cp\u003e\u003cstrong\u003eDepression \u0026amp; Anxiety\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eEllis et al. (2011)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAustralia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e39;\u003c/p\u003e\n \u003cp\u003e77%\u003c/p\u003e\n \u003cp\u003efemale, 23% male\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e19.67 (1.66)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUniversity Students experiencing low-to-moderate depression \u0026amp; anxiety\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 x 1-hour sessions over 3 weeks working through the content of the MoodGarden website:\u003c/p\u003e\n \u003cp\u003ea. Tools for self-management\u003c/p\u003e\n \u003cp\u003eb. Bulletins on lifestyle management\u003c/p\u003e\n \u003cp\u003ec. Discussions on effective treatments\u003c/p\u003e\n \u003cp\u003ed. Messageboard for peer-based support\u003c/p\u003e\n \u003cp\u003ee. Blogs and Charts\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1. MoodGym\u003c/p\u003e\n \u003cp\u003eFive modules of online CBT:\u003c/p\u003e\n \u003cp\u003ea. Introduction to CBT\u003c/p\u003e\n \u003cp\u003eb. Reducing dysfunctional thinking\u003c/p\u003e\n \u003cp\u003ec. Overcoming negative feelings\u003c/p\u003e\n \u003cp\u003ed. Identifying stress and relaxation\u003c/p\u003e\n \u003cp\u003eProblem-solving strategies and enhancing relationships\u003c/p\u003e\n \u003cp\u003eControl: No intervention\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eLived experience with a mood disorder\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNot reported\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMulfinger et al. (2018)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGermany\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e98;\u003c/p\u003e\n \u003cp\u003e69% female, non-binary N/A\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e15.75 (1.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eInpatients and outpatients with Anxiety and/or Depression\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3 x 2-hour sessions weekly over 3 weeks of Honest, Open, Proud (HOP):\u003c/p\u003e\n \u003cp\u003eThemes:\u003c/p\u003e\n \u003cp\u003ea. Challenging beliefs or self-stigma\u003c/p\u003e\n \u003cp\u003eb. Pros \u0026amp; cons of disclosure\u003c/p\u003e\n \u003cp\u003ec. The right person\u003c/p\u003e\n \u003cp\u003ed. Telling one\u0026apos;s story\u003c/p\u003e\n \u003cp\u003ee. Role of solidarity and peer support\u003c/p\u003e\n \u003cp\u003eWorkbooks contained vignettes, first-person accounts, worksheets, tables and role-plays.\u003c/p\u003e\n \u003cp\u003e1 young expert and 1 young peer worker\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTAU\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eYoung adult peer with lived experience of Mental Illness\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePeer facilitators were trained by researchers and conducted a practice session.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"9\"\u003e\n \u003cp\u003e\u003cstrong\u003eFirst Episode Psychosis\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAlvarez-Jimenez et al. (2021)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAustralia\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e170;\u003c/p\u003e\n \u003cp\u003e47.1% female, 52.9% male\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20.91 (2.88)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eYoung people in recovery of First Episode Psychosis, exiting early intervention service\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMean Number of Individual posts and/or comments\u0026thinsp;=\u0026thinsp;21.49 (SD\u0026thinsp;=\u0026thinsp;41.71) over 18 months (Mean\u0026thinsp;=\u0026thinsp;8.15 (SD\u0026thinsp;=\u0026thinsp;5.65)) of Online Social Network:\u003c/p\u003e\n \u003cp\u003ea. Icebreakers\u003c/p\u003e\n \u003cp\u003eb. user-generated threads\u003c/p\u003e\n \u003cp\u003ec. content related to mental health\u003c/p\u003e\n \u003cp\u003ed. content of general interest\u003c/p\u003e\n \u003cp\u003eVocational training:\u003c/p\u003e\n \u003cp\u003ea. Ask the expert\u003c/p\u003e\n \u003cp\u003eb. individualized online vocational support\u003c/p\u003e\n \u003cp\u003eOnline Therapy w/ health professional:\u003c/p\u003e\n \u003cp\u003ea. Online pathways \u0026ndash; distinct themes on recovery\u003c/p\u003e\n \u003cp\u003eb. Online Steps - interactive therapy modules\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eControl: TAU\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePeer workers had lived experience in mental illness.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNot Reported\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"9\"\u003e\n \u003cp\u003e\u003cstrong\u003ePrevention in Eating Disorders\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBecker et al. (2010)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e102;\u003c/p\u003e\n \u003cp\u003e100%\u003c/p\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e18.73 (0.72)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUniversity students (Freshman or Sophomore)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 x 2-hour sessions over\u003c/p\u003e\n \u003cp\u003e2 weeks of Cognitive Dissonance:\u003c/p\u003e\n \u003cp\u003ea. Group Discussions on the thin ideal\u003c/p\u003e\n \u003cp\u003eb. Group Brainstorming on cost on the thin ideal\u003c/p\u003e\n \u003cp\u003ec. Homework body appreciation\u003c/p\u003e\n \u003cp\u003ed. Role-plays on resisting the thin ideal\u003c/p\u003e\n \u003cp\u003ee. Shared lived experiences from peer-leaders and peers in the sessions.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1. Media Advocacy:\u003c/p\u003e\n \u003cp\u003ea. Watch Videos\u003c/p\u003e\n \u003cp\u003eb. Group Discussions of thin ideal\u003c/p\u003e\n \u003cp\u003ec. Group Brainstorming cost on the thin ideal\u003c/p\u003e\n \u003cp\u003ed. Food \u0026amp; exercise diaries\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePeer-leaders with past participation in the program and a member or the sorority\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4.5 hours experiential training sessions. Peer-leaders trained in teams (3\u0026ndash;4 peer-leaders at a time).\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCiao et al. (2021)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTrial 1\u003c/p\u003e\n \u003cp\u003eN\u0026thinsp;=\u0026thinsp;98;\u003c/p\u003e\n \u003cp\u003efemale 80%\u003c/p\u003e\n \u003cp\u003emale 14%\u003c/p\u003e\n \u003cp\u003enon-binary 6%\u003c/p\u003e\n \u003cp\u003eTrial 2 N\u0026thinsp;=\u0026thinsp;141;\u003c/p\u003e\n \u003cp\u003e80% female\u003c/p\u003e\n \u003cp\u003e15% male\u003c/p\u003e\n \u003cp\u003e5% non-binary\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTrial 1 20.39 (4.12)\u003c/p\u003e\n \u003cp\u003eTrial 2\u003c/p\u003e\n \u003cp\u003e19.66 (2.53)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUniversity students interested\u003c/p\u003e\n \u003cp\u003ein a body acceptance program\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 x 2-hour group sessions over 2 weeks of the \u0026lsquo;EVERYbody Project\u0026rsquo; involving 4\u0026ndash;9 participants\u003c/p\u003e\n \u003cp\u003ea. Group Discussions\u003c/p\u003e\n \u003cp\u003eb. Role-Plays\u003c/p\u003e\n \u003cp\u003ec. Group Activities\u003c/p\u003e\n \u003cp\u003eTrial 1: 1 x Expert-leader \u0026amp; 2 peer-leaders\u003c/p\u003e\n \u003cp\u003eTrial 2: 3\u0026ndash;4 x peer-leaders\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTrial 1: Control: No intervention\u003c/p\u003e\n \u003cp\u003eTrial 2:\u003c/p\u003e\n \u003cp\u003eVideo Intervention\u003c/p\u003e\n \u003cp\u003ea. Watch Videos\u003c/p\u003e\n \u003cp\u003eb. Reflective Writing\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePeer-leaders with past participation in the female program\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTraining followed protocol used in the peer-led \u0026lsquo;Body Project\u0026rsquo;\u003c/p\u003e\n \u003cp\u003eTrial 1\u003c/p\u003e\n \u003cp\u003e2 days of training (16 hours).\u003c/p\u003e\n \u003cp\u003eTrial 2\u003c/p\u003e\n \u003cp\u003e2 days of training (16 hours)\u003c/p\u003e\n \u003cp\u003ewith discussion on group facilitation skills and role plays on difficult diverse situations.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eKilpela et al. (2016)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUSA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e180;\u003c/p\u003e\n \u003cp\u003e62% female, 38% male\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e19.9 (1.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUniversity students\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2 x 2-hour sessions over 2 weeks of \u0026lsquo;Body Project\u0026rsquo;\u003c/p\u003e\n \u003cp\u003ea. Group Discussions on the thin ideal contrasting healthy ideal, the origin of the thin-ideal, past pressures\u003c/p\u003e\n \u003cp\u003eb. Group Brainstorming on cost on the thin ideal and combating the thin-ideal\u003c/p\u003e\n \u003cp\u003ec. Homework body appreciation, writing to a young person, challenging own behaviour\u003c/p\u003e\n \u003cp\u003ed. Role-plays on resisting the thin ideal\u003c/p\u003e\n \u003cp\u003ee. Shared lived experiences from peer-leaders and peers in the sessions.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eControl: Waitlist\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePeer-leaders with past participation in the program\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTrainer to Trainer method: Experience peer-leaders in the program trained new peer-leaders over two-days\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eResendel et al. (2021)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBrazil\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e74;\u003c/p\u003e\n \u003cp\u003e100%\u003c/p\u003e\n \u003cp\u003efemale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e20.5 (2.02)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUniversity students\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4 x 60-minute sessions over 4 weeks of \u0026lsquo;Body Project\u0026rsquo; led by two peer-leaders\u003c/p\u003e\n \u003cp\u003ea. Group discussions on the thin-ideal, body appreciation/concerns\u003c/p\u003e\n \u003cp\u003eb. Group brainstorming on the cost of the thin-ideal\u003c/p\u003e\n \u003cp\u003ec. Homework sessions on body appreciation\u003c/p\u003e\n \u003cp\u003ed. Role-plays on resisting the thin-ideal\u003c/p\u003e\n \u003cp\u003ee. Engaged in further body activism\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eControl: No intervention\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHave experience in Intuitive Eating and past body image concerns and currently a university student\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eReferences the Body Project website: Therefore, training on the concept and rationale of the body project, in group discussions and role plays, using the manual for guidance. Possibly some practice runs with feedback from supervisors.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"9\"\u003e\n \u003cp\u003e\u003cstrong\u003ePrevention in Substance Use\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGerman et al. (2012)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThailand\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e983;\u003c/p\u003e\n \u003cp\u003e27.3% female\u003c/p\u003e\n \u003cp\u003e72.7% male\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMedian 19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUsed Meth-amphetamine\u003c/p\u003e\n \u003cp\u003e\u0026amp; engaged\u003c/p\u003e\n \u003cp\u003ein sex at\u003c/p\u003e\n \u003cp\u003eleast 3 times\u003c/p\u003e\n \u003cp\u003ein the last 3 months, at a Research Community\u003c/p\u003e\n \u003cp\u003eCentre\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7 x 1.5-2.5hr group session twice weekly over 1 month of \u0026lsquo;Peer Education\u0026rsquo;, in groups of 8\u0026ndash;12 participants:\u003c/p\u003e\n \u003cp\u003ea. Drug use on individuals\u003c/p\u003e\n \u003cp\u003eb. Drug use and Social influences\u003c/p\u003e\n \u003cp\u003ec. Drug use and Sex\u003c/p\u003e\n \u003cp\u003ed. Drug use and Risk Behaviours\u003c/p\u003e\n \u003cp\u003ee. Family and Community\u003c/p\u003e\n \u003cp\u003ef. Community Project\u003c/p\u003e\n \u003cp\u003eg. Review and Graduation\u003c/p\u003e\n \u003cp\u003e2 boosters (3 \u0026amp; 6-month mark).\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7 x 1.5-2.5hr group session twice weekly over 1 month of \u0026lsquo;Life Skills\u0026rsquo;, in groups of 8\u0026ndash;12 participants:\u003c/p\u003e\n \u003cp\u003ea. Understanding Life\u003c/p\u003e\n \u003cp\u003eb. Decision Making Skills and Old Friends/New Friends\u003c/p\u003e\n \u003cp\u003ec. Danger of Drug Use\u003c/p\u003e\n \u003cp\u003ed. Sexually Infectious Diseases\u003c/p\u003e\n \u003cp\u003ee. How Important is Stress?\u003c/p\u003e\n \u003cp\u003ef. Emotion Management and Life Goals\u003c/p\u003e\n \u003cp\u003eg. Envelope of Goodness and Graduation\u003c/p\u003e\n \u003cp\u003eNetwork groups for participants in both Peer Education and Life Skills received no intervention\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eEarly 20s, participated in an earlier study as part of the ethnography team\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eResearchers trained peer facilitators in a 1 week long intensive training session on building a prosocial role and to increase positive communication interactions with peers.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003ctable border=\"1\" id=\"Tab3\"\u003e\n \u003ccaption\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eSummary results of anxiety and depression outcomes of included trials\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\u0026nbsp;\u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eEllis et al. (2011)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMulfinger et al. (2018)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eAlvarez-Jimenez et al. (2021)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eBecker et al. (2010)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCiao et al. (2021)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eKipela et al. (2016)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eResende et al. (2021)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eGerman et al. (2012)\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMeasures\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAnxiety and Depression (DASS-21);\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDepression (CESDS)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDepression (CDSS)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNegative affect (PANAS-X)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNegative Affect (PANAS)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNegative Affect (PANAS)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNegative Affect (PANAS-B)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDepression (CESD)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eGroups\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOnline Peer Support (n\u0026thinsp;=\u0026thinsp;13)\u003c/p\u003e\n \u003cp\u003eOnline CBT (n\u0026thinsp;=\u0026thinsp;13)\u003c/p\u003e\n \u003cp\u003eControls (n\u0026thinsp;=\u0026thinsp;13)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHOP (n\u0026thinsp;=\u0026thinsp;49)\u003c/p\u003e\n \u003cp\u003eControl (TAU;\u003c/p\u003e\n \u003cp\u003en\u0026thinsp;=\u0026thinsp;49)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eHoryzons\u0026thinsp;+\u0026thinsp;TAU\u003c/p\u003e\n \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;84)\u003c/p\u003e\n \u003cp\u003eControl (TAU; n\u0026thinsp;=\u0026thinsp;86)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCognitive Dissonance (n\u0026thinsp;=\u0026thinsp;53)\u003c/p\u003e\n \u003cp\u003eControl (Media Advocacy; n\u0026thinsp;=\u0026thinsp;49)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eTrial 1: Everybody Project (w/ expert - and peer-leaders; n\u0026thinsp;=\u0026thinsp;48)\u003c/p\u003e\n \u003cp\u003eControl (Waitlist; n\u0026thinsp;=\u0026thinsp;50)\u003c/p\u003e\n \u003cp\u003eTrial 2: Everybody Project (w/ peer-leaders only; n\u0026thinsp;=\u0026thinsp;65)\u003c/p\u003e\n \u003cp\u003eControl (Video Intervention; n\u0026thinsp;=\u0026thinsp;76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eMixed-Gender (n\u0026thinsp;=\u0026thinsp;77,\u003c/p\u003e\n \u003cp\u003eFemale-Only (n\u0026thinsp;=\u0026thinsp;65)\u003c/p\u003e\n \u003cp\u003eControl (waitlist;\u003c/p\u003e\n \u003cp\u003en\u0026thinsp;=\u0026thinsp;38)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBody Project (n\u0026thinsp;=\u0026thinsp;38)\u003c/p\u003e\n \u003cp\u003eControl (n\u0026thinsp;=\u0026thinsp;36)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ePeer Education\u003c/p\u003e\n \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;209)\u003c/p\u003e\n \u003cp\u003eControl (Network Peer Education;\u003c/p\u003e\n \u003cp\u003en\u0026thinsp;=\u0026thinsp;286)\u003c/p\u003e\n \u003cp\u003eLife Skills\u003c/p\u003e\n \u003cp\u003e(n\u0026thinsp;=\u0026thinsp;206)\u003c/p\u003e\n \u003cp\u003eControl (Network Life Skills;\u003c/p\u003e\n \u003cp\u003en\u0026thinsp;=\u0026thinsp;282)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"9\"\u003e\n \u003cp\u003e\u003cstrong\u003eAnxiety and Depression Results\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAnxiety\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eY*;\u003c/strong\u003e online CBT, \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.99, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.03, and\u003c/p\u003e\n \u003cp\u003eonline peer support, \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.95, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.01, compared to controls.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eDepression\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ens\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ens/\u003cstrong\u003eY* FU6W;\u003c/strong\u003e HOP, \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.72, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.001) compared to controls\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003ens\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eY*\u003c/strong\u003e Intervention:\u003c/p\u003e\n \u003cp\u003epost-intervention mean difference\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;4.5251, \u003cem\u003eSE\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.7279; \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.0001), compared to baseline.\u003c/p\u003e\n \u003cp\u003eControl: ns\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNegative Affect\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eY*\u003c/strong\u003e Intervention: postintervention, \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.51, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05;\u003c/p\u003e\n \u003cp\u003e8 weeks \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.25, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05;\u003c/p\u003e\n \u003cp\u003e8 months \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.35, \u003cem\u003ep\u003c/em\u003e \u0026lt;. 05;\u003c/p\u003e\n \u003cp\u003e14 months \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.48, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05, compared to baseline.\u003c/p\u003e\n \u003cp\u003eControl: postintervention, ns;\u003c/p\u003e\n \u003cp\u003e8 weeks, ns;\u003c/p\u003e\n \u003cp\u003e8 months \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.58, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05;\u003c/p\u003e\n \u003cp\u003e14 months \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.34, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05, compared to baseline.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eY*\u003c/strong\u003e Trial 1 EVERYbody (w/ expert - and peer-leaders): postintervention \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.56, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05;\u003c/p\u003e\n \u003cp\u003e1-month \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.42, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05, compared to controls;\u003c/p\u003e\n \u003cp\u003egroup x time interaction (\u003cem\u003eb\u003c/em\u003e\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;0.03, \u003cem\u003et\u003c/em\u003e\u0026thinsp;=\u0026thinsp;\u0026minus;\u0026thinsp;4.45, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.0001)\u003c/p\u003e\n \u003cp\u003eTrial 2 EVERYbody (w/ peer-leaders only): postintervention \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.01, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05;\u003c/p\u003e\n \u003cp\u003e1-month \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.10, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05 compared to controls;\u003c/p\u003e\n \u003cp\u003egroup x time interaction, ns.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eY*\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003ea\u003c/strong\u003e\u003c/sup\u003e Males\u003c/p\u003e\n \u003cp\u003eIntervention:\u003c/p\u003e\n \u003cp\u003eMales in Mixed Gender group:\u003c/p\u003e\n \u003cp\u003epostintervention, \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.40, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.0080;\u003c/p\u003e\n \u003cp\u003e2-month ns;\u003c/p\u003e\n \u003cp\u003e6-month ns, compared to controls.\u003c/p\u003e\n \u003cp\u003eFemales in Mixed Gender group: ns.\u003c/p\u003e\n \u003cp\u003eFemales Intervention:\u003c/p\u003e\n \u003cp\u003eFemale Only group: ns.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003ens/Y*\u003c/strong\u003e\u003csup\u003e\u003cstrong\u003eb\u003c/strong\u003e\u003c/sup\u003e \u003cstrong\u003eFU24W\u003c/strong\u003e Intervention: \u003cem\u003ed\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.60 \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;.05) compared to controls.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eParticipant Feedback\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eOnline peer support compared to online CBT:\u003c/p\u003e\n \u003cp\u003e\u0026bull; More helpful,\u003c/p\u003e\n \u003cp\u003e\u0026bull; More enjoyable\u003c/p\u003e\n \u003cp\u003e\u0026bull; Equally recommended\u003c/p\u003e\n \u003cp\u003e\u0026bull; One-third reported they would continue using online peer support\u003c/p\u003e\n \u003cp\u003e\u0026bull; Two-thirds reported they would continue using online CBT \u0026ndash; possibly because the online CBT group were still feeling more anxious than the online peer-support group.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026bull; Peer-leader was viewed as an inspiring role-model\u003c/p\u003e\n \u003cp\u003e\u0026bull; Enjoyed learning about their real-life experiences.\u003c/p\u003e\n \u003cp\u003e\u0026bull; Relief to talk about disclosure in a safe space.\u003c/p\u003e\n \u003cp\u003e\u0026bull; facilitated openness, trust, and respect within the group interactions\u003c/p\u003e\n \u003cp\u003e\u0026bull; Some materials were deemed too theoretical, demanding, and hard to concentrate on or too detailed.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026bull; Some participants had positive experiences of social connection on Horyzons.\u003c/p\u003e\n \u003cp\u003e\u0026bull; Others did not due to social anxiety, paranoia and confusion within the social network of Horyzons.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026bull; Participants preferred the Cognitive Dissonance intervention over the Control intervention.\u003c/p\u003e\n \u003cp\u003e\u0026bull; Both interventions were deemed useful\u003c/p\u003e\n \u003cp\u003e\u0026bull; Suggested the Control intervention may be a good follow up or refresher intervention.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026bull; Experts were able to\u003c/p\u003e\n \u003cp\u003eaddress diverse body images (various gender-, sexual-, and racial-identities) better than peer-leaders.\u003c/p\u003e\n \u003cp\u003e\u0026bull; Peer-leaders lacked lived experience in all diverse body images, which may have hindered them in connecting with all the participants.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u0026bull; Adding males to the Body Project created a Mixed Gender Group, which established a warmer collaborative (versus activating) vibe,\u003c/p\u003e\n \u003cp\u003e\u0026bull; Normally the Body Project creates an angry vibe against the thin-ideal through the historical struggle women have had against the thin-ideal.\u003c/p\u003e\n \u003cp\u003e\u0026bull; This warmer vide was carried over to the Female Only Group, which may explain a lack of effects among females.\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eNot reported\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eThe research site (known as \u0026ldquo;House of Friends\u0026rdquo;):\u003c/p\u003e\n \u003cp\u003e\u0026bull; Allowed participants to gather and socialise informally with each other.\u003c/p\u003e\n \u003cp\u003e\u0026bull; Was a safe place,\u003c/p\u003e\n \u003cp\u003eas there was no social stigma or fear of being arrested, which was common for participants in the general community.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"9\"\u003e\u003cem\u003eNote\u003c/em\u003e: Y*(bolded)\u0026thinsp;=\u0026thinsp;significant result, ns\u0026thinsp;=\u0026thinsp;non-significant, FU\u0026thinsp;=\u0026thinsp;Follow-up, (number)W/M\u0026thinsp;=\u0026thinsp;number of weeks or months, Note: DASS-21\u0026thinsp;=\u0026thinsp;Depression, Anxiety and Stress Scale, CESDS\u0026thinsp;=\u0026thinsp;Center for Epidemiologic Studies Depression Scale, CDSS =- Calgary Depression Scale for Schizophrenia, PANSS\u0026thinsp;=\u0026thinsp;Positive and Negative Syndrome Scale, PANASX\u0026thinsp;=\u0026thinsp;Positive and Negative Affect Schedule \u0026ndash; Revised, PANAS\u0026thinsp;=\u0026thinsp;Positive and Negative Affect Schedule, PANAS-B\u0026thinsp;=\u0026thinsp;Positive and Negative Affect Schedule, CESD\u0026thinsp;=\u0026thinsp;Centers for Epidemiological Studies Depression Scale.\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"9\"\u003ea Kipela et al. (2016) found negative affect only decreased with the males in their mixed-gender group, not with the females in the mixed-gender group or with the female only group.\u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"9\"\u003eb Resende et al. (2021) found negative affect only decreased at the 24-week follow-up, not at post-intervention, or four weeks follow-up.\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/div\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec16\"\u003e\n \u003ch2\u003eDepression and anxiety\u003c/h2\u003e\n \u003cp\u003eThe first study on depression and anxiety was undertaken in Australia with University students, experiencing low-to-moderate depression \u0026amp; anxiety (\u003cspan class=\"CitationRef\"\u003e30\u003c/span\u003e). Students were randomised into one of two experimental groups or a no-intervention control group. The first group engaged in online CBT via \u0026lsquo;MoodGym\u0026rsquo; and the second group engaged in an online peer support group via \u0026lsquo;MoodGarden\u0026rsquo; (see Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e for intervention characteristics). \u0026lsquo;MoodGarden\u0026rsquo; involved access to the established non-profit website run by volunteers with lived experience of a mood disorder. Peer workers mediated the message board that the participants posted on. Compared to the control group, post-intervention measures showed that the online CBT and online peer support significantly reduced anxiety symptoms (see Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). However, neither intervention affected depression symptoms. \u0026lsquo;MoodGarden\u0026rsquo; participants reported higher perceived online social support compared to the \u0026lsquo;MoodGym\u0026rsquo; and control groups (see Supplementary File 4).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec17\"\u003e\n \u003ch2\u003eAny mental illness\u003c/h2\u003e\n \u003cp\u003eThe second study (\u003cspan class=\"CitationRef\"\u003e31\u003c/span\u003e) was undertaken in Germany with teenagers (mean age 16) experiencing depression and anxiety, mainly in inpatient settings. They compared an intervention known as Honest, Open, Proud (HOP) to a treatment as usual (TAU) control group (see Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e for intervention details). This group program was co-facilitated by a peer and aimed to support individuals in their decisions to disclose their mental illness and therefore reduce the impact of stigma for adolescents. Depressive symptoms were measured as secondary outcomes and showed no reduction post-intervention; however, at six-week follow-up, depressive symptoms had significantly reduced (see Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e). There was a significant difference between groups in favour of the intervention group for the primary endpoints (reduction in stigma stress post intervention and improvement in quality of life at follow up). Other positive effects found that may overlap with peer support mechanisms included help-seeking intentions (family/friends, professionals), stage of recovery, and empowerment (self-esteem, optimism; see Supplementary File 4). No effect was found for social withdrawal or hopelessness. Attrition rates between post-intervention and follow-up were the same for both groups (n\u0026thinsp;=\u0026thinsp;11); reasons included being uncontactable or refusing to complete follow-up.\u003c/p\u003e\n \u003cp\u003eThis study was the only included study to conduct a cost-effectiveness analysis aimed at calculating value for money of delivery of the intervention. HOP\u0026rsquo;s total costs, including, for example, the training and employment of peers and professionals and overhead costs, were calculated and compared to British annual costs per young person (aged 5 to 15) where the National Institute for Health and Care Excellence (NICE) uses a cost-effectiveness threshold of \u0026pound;20,000\u0026ndash;\u0026pound;30,000/QALY (\u003cspan class=\"CitationRef\"\u003e32\u003c/span\u003e). Based on the utility gains (0.044), HOPS was deemed to be a cost-effective intervention, even if those gains only lasted for two months (at a cost of \u0026euro;20,533/QALY), but more so if the gains continued at six months (\u0026euro;6,969/QALY).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec18\"\u003e\n \u003ch2\u003eFirst Episode Psychosis\u003c/h2\u003e\n \u003cp\u003eOne study that assessed depression in young people with a recent onset psychotic disorder was identified (\u003cspan class=\"CitationRef\"\u003e33\u003c/span\u003e). The intervention \u0026lsquo;Horyzons\u0026rsquo; used the \u0026lsquo;Moderated Online Social Therapy\u0026rsquo; model, which integrates interactive online therapy, peer-to-peer online social networking, peer moderation, and expert support (see Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e). While the intervention was shown to improve vocational functioning and reduce hospital emergency service use compared to TAU, no effect was found for depression symptoms (\u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;.42) or any peer-support related constructs (e.g. loneliness; see Supplementary File 4).\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec19\"\u003e\n \u003ch2\u003eEating disorders\u003c/h2\u003e\n \u003cp\u003eFour studies tested slightly different versions of a lived-experience peer-worker led intervention known as the Body Project Collaborative (see Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e2\u003c/span\u003e for intervention details), which aims to prevent eating disorders and body dissatisfaction. All studies were successful in reducing body image concerns and eating disorder risk. All involved University students, three in the USA (\u003cspan class=\"CitationRef\"\u003e34\u003c/span\u003e\u0026ndash;\u003cspan class=\"CitationRef\"\u003e36\u003c/span\u003e), and one in Brazil (\u003cspan class=\"CitationRef\"\u003e37\u003c/span\u003e). All utilised the Positive and Negative Affect Schedule, with the effect of these interventions on negative affect varying across trials. Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e shows two (\u003cspan class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e35\u003c/span\u003e) found significant reduction of negative affect over time. Resende and colleagues (\u003cspan class=\"CitationRef\"\u003e37\u003c/span\u003e) found an increase in self-esteem at post-invention and 24 weeks (see Supplementary File 4). However, they only found a significant reduction in negative affect at 24 weeks. Kilpela, Blomquist (\u003cspan class=\"CitationRef\"\u003e36\u003c/span\u003e) reported a significant reduction of negative affect only in male participants. Overall peer-led interventions across all studies had significantly better outcomes compared to control groups.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec20\"\u003e\n \u003ch2\u003eSubstance use\u003c/h2\u003e\n \u003cp\u003eThe final trial targeted young methamphetamine users in Thailand (\u003cspan class=\"CitationRef\"\u003e38\u003c/span\u003e). Secondary analysis of the trial demonstrated a significant effect for depression symptoms; however, this was not the primary aim of the trial. The intervention was a \u0026lsquo;Peer Education\u0026rsquo; group that aimed to teach participants to reduce their methamphetamine use and sexual risk behaviours as well as how to communicate learnings from the group with their methamphetamine using peers or sexual partners. The authors hypothesised the intervention had a significant impact on depression (see Table\u0026nbsp;\u003cspan class=\"InternalRef\"\u003e3\u003c/span\u003e) due to the intervention encouraged participants to build a prosocial role and increase positive communication with peers and family members. The emphasis on social relationships and contributing to the community may have affected feelings of isolation and stigma, particularly within a collectivist culture such as Thailand.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv class=\"Section2\" id=\"Sec21\"\u003e\n \u003ch2\u003eQuality of studies\u003c/h2\u003e\n \u003cp\u003eSupplementary File 5 shows the overall quality of the studies was good using the Critical Appraisal Skills Programme. Importantly, six studies were partially or fully unclear on blinding procedures. Four studies did not account for missing data and four studies did not conduct \u003cem\u003ea priori\u003c/em\u003e power analyses. No measures of fidelity were used.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Discussion","content":"\u003cdiv id=\"Sec23\" class=\"Section2\"\u003e \u003ch2\u003eOverall findings\u003c/h2\u003e \u003cp\u003eIn this review, we aimed to identify and describe studies of peer support for young people to improve symptoms of depression or anxiety. We sought to investigate in which ways, in which contexts, and for whom, peer support appears to work or not work. Despite there being a range of controlled trials testing peer support interventions for adults with mental health challenges such as anxiety and depression (\u003cspan additionalcitationids=\"CR40\" citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e), very few have been conducted in young people. We were only able to identify two trials specifically targeting anxiety or depression, and there were limitations across studies that we will now discuss.\u003c/p\u003e \u003cp\u003eIn total, six studies were conducted in high income countries and two in low- and middle-income countries. The most common setting was Universities (5 studies), with only two mental health service settings and one research community centre. Aside from the considerable lack of geographical diversity, the settings also limit our knowledge of the context in which peer support might work, given that only a small proportion of young people attend University or mental health services. Many studies in a broader range of settings were excluded because the peer worker role did not require lived experience. The variability of this requirement, which is mirrored in research with adults (\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e), is just one factor that is indicative of the generally heterogeneous array of definitions of peer support, in terms of the setting, intervention, and peer. We note that the core values of peer support are based on lived experience, which is why this was deemed an essential criterion for inclusion.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec24\" class=\"Section2\"\u003e \u003ch2\u003eIn what contexts does peer support work?\u003c/h2\u003e \u003cp\u003eImportantly, two studies (\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e) successfully and safely tested online peer support interventions. Understanding how peer support can be delivered remotely is important in the context of the current COVID-19 global pandemic, and complements work done on peer-to-peer support (\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e). As young people globally grapple with the increase in social isolation, uncertainty about the future, and other experiences that are related to poorer mental health, having sufficient workforce supply to serve the demand of those seeking help is essential. Although it should not be seen as \u0026lsquo;cheap labour\u0026rsquo;, with the right support structures in place (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e), peer workers are able to be trained more readily than other professions. One study specifically assessed and reported no adverse effects (\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e); participant feedback from the other studies were generally good (see Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) and successful interventions were found to be acceptable, suitable, and cost-effective, in line with adult reviews (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e). It is also easier to ensure diversity in the workforce through peer support, as the barriers to formal education pathways that exist for many minority groups are less prominent in peer work. As our steering group members pointed out, better representation from minority groups in the workforce is more likely to result in culturally safer environments.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec25\" class=\"Section2\"\u003e \u003ch2\u003eFor whom does peer support work?\u003c/h2\u003e \u003cp\u003eIn terms of understanding who peer support may or may not work for, we were unable to answer this. Only two studies focused specifically on depression and anxiety, with the rest focused on relapse prevention after first episode psychosis, substance use disorders and four focused on the prevention of eating disorders. In line with adult literature, depression related measures were more commonly used and anxiety related measures were largely absent (\u003cspan additionalcitationids=\"CR40\" citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e). Unlike the adult peer support literature as reviewed by King, Simmons (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e), the studies we found in youth settings did not aim to measure the impact of peer support, any overlapping measures such as hope and empowerment were tied back to their initial study aims.\u003c/p\u003e \u003cp\u003eFurther, the mean age of participants in all but one trial fell in the young adult range (19\u0026ndash;21 years). Peer support has been widely tested in educational settings with children and adolescents; however, peers are not required to have lived experience, meaning they don\u0026rsquo;t contribute to our understanding of lived experience as an active ingredient or align with the core principles of peer support in a mental health context. Developing and testing lived experience-based peer support in younger groups requires careful consideration of what age one might expect a peer worker to be (\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e). While having a peer worker be as close in age as possible, it also makes good sense to have slightly older peer workers who have experienced both relevant mental health challenges and some experiences of treatment and recovery. Overall, it is not yet discernible who peer support does and does not work for.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec26\" class=\"Section2\"\u003e \u003ch2\u003eWhy might peer support work?\u003c/h2\u003e \u003cp\u003eSpecific mechanisms of action for peer support in youth depression and anxiety are yet to be proposed and tested. The lack of clarity in the evidence we did find (e.g. definition of a peer worker, what the intervention is, and what peer support values or principles were adhered to) makes it even more difficult to understand mechanisms. As a starting point to address this gap, we drew on the findings of this review and previous literature from adults (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e, \u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e), together with input from the steering groups and expert interviews that informed this review, to propose a preliminary model for the mechanisms of action regarding peer support for youth anxiety and depression (see Fig.\u0026nbsp;2). However, empirical work that tests this proposed model is required.\u003c/p\u003e \u003cp\u003eOther critical gaps in the literature include exploring the best ways to test the \u0026lsquo;effectiveness\u0026rsquo; of peer support interventions in this area. When our systematic review failed to identify many studies, we searched for existing youth peer support programs and checked for any related research or evaluation. We found a number of programs operating in a range of countries, although we did not find any associated evaluation, suggesting a lost opportunity to properly understand how these programs are helping young people who experience depression and anxiety. In contrast, the steering groups responded optimistically, suggesting there is a wealth of knowledge to draw on from the programs run by groups who are out helping young people on the ground.\u003c/p\u003e \u003cp\u003eHarnessing this knowledge will require careful consideration of what types of research designs and methodologies are appropriate for peer support (\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e). Much of mental health research is based on a medical/clinical model that focuses on individual deficits (\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e). This is at odds with both the theoretical underpinnings of peer support models (e.g. Intentional Peer Support) (\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e) and also the collectivist nature of many cultures worldwide, as recognised by one of the trials identified in our review (\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e). Focusing on the programs already operating, mainly in high income countries, is essential in order to capture the lessons already learned about how people with lived experience of anxiety and depression can help their peers. Understanding how peer support programs operate effectively in low resource settings and in varying cultural contexts, yet retain relevant core values of peer support, is equally as important. Furthermore, peer support has also been associated with engaging in generative actions such as helping others, changing organisations and systems, and sharing personal stories (\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e), which can lead to a range of psychosocial benefits on both the individual and relational interpersonal levels (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eRegardless of the research setting and cultural context, this review highlighted a number of areas requiring clarity (see Supplementary File 6). First of all, role-specific definitions of \u003cem\u003epeer\u003c/em\u003e and \u003cem\u003elived experience\u003c/em\u003e are vital, including relevancy of age, characteristics and type of lived experience (e.g. experience of mental health challenges, receipt of treatment, and recovery). Secondly, detailed descriptions of peer support interventions are required that explain: 1) the theoretical underpinning, core values and principles of the intervention; 2) how fidelity to is assessed; 3) the nature of the role and how the peer worker was supported to adhere to these values and principles in their role (i.e. training and supervision). Further, given that a number of barriers to implementing peer work in practice have been identified in adult settings (e.g. (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e)) and are likely exacerbated in youth settings (\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e), future research should use designs incorporating implementation science methodologies from the outset. There are also unresolved issues beyond the scope of research, such as what happens to youth peer workers when they age out of the age-related role requirements. All of these elements were generally lacking in the literature we reviewed, but are critical for moving the field forward.\u003c/p\u003e \u003cp\u003eLastly, only two of the studies used a co-design approach to intervention development. These interventions were both digital in nature, which is unsurprising given that user-centred design methodologies are common in the development of digital solutions. Involving young people with lived experience of anxiety and depression in all aspects of peer support intervention design and testing will improve the quality and significance of such endeavours (\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e). Similarly, involvement from experienced youth peer workers will also help ensure interventions are appropriate, feasible, and meaningful. Drawing on the existing knowledge held by the youth peer workforce and young people who have accessed peer support interventions is the most promising avenue for determining the ways in which peer support is an active ingredient for youth depression and anxiety.\u003c/p\u003e \u003c/div\u003e"},{"header":"List of abbreviations","content":"\u003cp\u003eCASP Critical Appraisal Skills Programme\u003c/p\u003e\n\u003cp\u003eCBT Cognitive Behavioural Therapy\u003c/p\u003e\n\u003cp\u003eHOP Honest, Open, Proud\u003c/p\u003e\n\u003cp\u003eNICE The National Institute for Health and Care Excellence\u003c/p\u003e\n\u003cp\u003eOEF Orygen Evidence Finder\u003c/p\u003e\n\u003cp\u003ePRISMA Preferred Reporting Items for Systematic Reviews and Meta-Analyses\u003c/p\u003e\n\u003cp\u003eQALY Quality adjusted life years\u003c/p\u003e\n\u003cp\u003eRCT Randomised controlled trial\u003c/p\u003e\n\u003cp\u003eSES Socio-economic status\u003c/p\u003e\n\u003cp\u003eTAU Treatment as usual\u003c/p\u003e\n\u003cp\u003eUSA United States of America\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo research participants were involved in this study. We worked with an international steering group of young adult peer workers and/or young adults who had received peer work. They contributed their expertise as advisors to the review, and provided consent to do so by completing an expression of interest form. They were not involved as research participants. We also sought advice from peer support experts, who were consulted to improve the quality of the review. In line with our institutional requirements, we did not have to seek ethical approval to involve either group as advisors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work was funded by a Wellcome Trust Mental Health Priority Area \u0026apos;Active Ingredients\u0026apos; 2021 commission awarded to MBS at Orygen and The University of Melbourne.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMBS and EB designed the review with assistance from AB. AB and MBS designed the search strategy and AB performed database searches. MBS, SC, AB and EB undertook screening. RM coordinated the steering group meetings. All authors contributed to the drafting of the manuscript, led by MBS. All authors read and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to acknowledge additional technical support from Sarah Bostock, Stefanie De Silva, Alicia Randell, Samantha Cooke, Kelly Allott, Nicola Acevedo, steering group members (Rafi Armanto, Nawira Baig Bte Istrar Baig, Diana Dimitrov, Aisling Dillon, Mahalia Dixon, Cassandra Jankovic, Kiera Jean Lowe, Lauren Luliani, Niamh Petrie, and one anonymous member), and experts who participated in interviews (Mikaela Basile, Michelle Blanchard, Naeem Dalal, Mardi Daley, Raffael Masuda, Janet Walker, and three anonymous interviewees).\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eKessler RC, Amminger GP, Aguilar-Gaxiola S, Alonso J, Lee S, Ustun TB. Age of onset of mental disorders: a review of recent literature. Curr Opin Psychiatry. 2007;20(4):359\u0026ndash;64.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYoung Minds Matter. The Mental Health of Children and Adolescents: Report on the Second Australian Child and Adolescent Survey of Mental Health and Wellbeing. Australian Government Department of Health,; 2013-14.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAuerbach RP, Mortier P, Bruffaerts R, Alonso J, Benjet C, Cuijpers P, et al. WHO World Mental Health Surveys International College Student Project: Prevalence and distribution of mental disorders. J Abnorm Psychol. 2018;127(7):623\u0026ndash;38.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eReavley NJ, Yap MB, Wright A, Jorm AF. Actions taken by young people to deal with mental disorders: findings from an Australian national survey of youth. Early Interv Psychiatry. 2011;5(4):335\u0026ndash;42.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHoulston C, Smith PK. The impact of a peer counselling scheme to address bullying in an all-girl London secondary school: a short-term longitudinal study. Br J Educ Psychol. 2009;79(Pt 1):69\u0026ndash;86.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChapman SA, Blash LK, Mayer K, Spetz J. Emerging Roles for Peer Providers in Mental Health and Substance Use Disorders. Am J Prev Med. 2018;54(6 Suppl 3):S267-S74.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTisdale C, Snowdon N, Allan J, Hides L, Williams P, de Andrade D. Youth Mental Health Peer Support Work: A Qualitative Study Exploring the Impacts and Challenges of Operating in a Peer Support Role. Adolescents. 2021;1(4):400\u0026ndash;11.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMead S, McNeil C. Peer support: What makes it unique? International Journal of Psychosocial Rehabilitation. 2006;30(3):207\u0026ndash;13.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWatson E. 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Effectiveness of peer support intervention on perinatal depression: A systematic review and meta-analysis. Journal of Affective Disorders. 2020;276:788\u0026ndash;96.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eField T, Diego M, Delgado J, Medina L. Peer support and interpersonal psychotherapy groups experienced decreased prenatal depression, anxiety cortisol. Early Human Development. 2013;89(9):621\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGopalan G, Lee SJ, Harris R, Acri MC, Munson MR. Utilization of peers in services for youth with emotional and behavioral challenges: A scoping review. J Adolesc. 2017;55:88\u0026ndash;115.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSimmons MB, Batchelor S, Dimopoulos-Bick T, Howe D. The Choice Project: Peer Workers Promoting Shared Decision Making at a Youth Mental Health Service. Psychiatr Serv. 2017;68(8):764\u0026ndash;70.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSimmons MB, Coates D, Batchelor S, Dimopoulos-Bick T, Howe D. The CHOICE pilot project: Challenges of implementing a combined peer work and shared decision-making programme in an early intervention service. Early Interv Psychiatry. 2018;12(5):964\u0026ndash;71.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRickwood DJ, Telford NR, Parker AG, Tanti CJ, McGorry PD. headspace - Australia's innovation in youth mental health: who are the clients and why are they presenting? Med J Aust. 2014;200(2):108\u0026ndash;11.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eIslam M, Khanam R, Kabir E. The use of mental health services by Australian adolescents with mental disorders and suicidality: Findings from a nationwide cross-sectional survey. 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Body Image. 2010;7(4):280\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCiao AC, Munson BR, Pringle KD, Roberts SR, Lalgee IA, Lawley KA, et al. Inclusive dissonance-based body image interventions for college students: Two randomized-controlled trials of the EVERYbody Project. J Consult Clin Psychol. 2021;89(4):301\u0026ndash;15.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKilpela LS, Blomquist K, Verzijl C, Wilfred S, Beyl R, Becker CB. The body project 4 all: A pilot randomized controlled trial of a mixed-gender dissonance-based body image program. International Journal of Eating Disorders. 2016;49(6):591\u0026ndash;602.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eResende TRO, Almeida M, dos Santos Alvarenga M, Brown TA, de Carvalho PHB. Dissonance-based eating disorder prevention improves intuitive eating: a randomized controlled trial for Brazilian women with body dissatisfaction. Eating and Weight Disorders. 2021.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGerman D, Sutcliffe CG, Sirirojn B, Sherman SG, Latkin CA, Aramrattana A, et al. Unanticipated effect of a randomized peer network intervention on depressive symptoms among young methamphetamine users in Thailand. Journal of Community Psychology. 2012;40(7):799\u0026ndash;813.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eField T, Diego M, Delgado J, Medina L. Peer support and interpersonal psychotherapy groups experienced decreased prenatal depression, anxiety and cortisol. Early Hum Dev. 2013;89(9):621\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang R, Yan C, Tian Y, Lei B, Yang D, Liu D, et al. Effectiveness of peer support intervention on perinatal depression: A systematic review and meta-analysis. J Affect Disord. 2020;276:788\u0026ndash;96.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePfeiffer PN, Heisler M, Piette JD, Rogers MA, Valenstein M. Efficacy of peer support interventions for depression: a meta-analysis. Gen Hosp Psychiatry. 2011;33(1):29\u0026ndash;36.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSuresh R, Alam A, Karkossa Z. Using Peer Support to Strengthen Mental Health During the COVID-19 Pandemic: A Review. Frontiers in Psychiatry. 2021;12(1119).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFava N, O'Bree B, Randall R, Kennedy H, Olsen J, Matenson E, et al. Youth Peer Work: Building a Strong and Supported Youth Peer Workforce. In: Meagher J, Stratford A, Jackson F, Jayakody E, Fong T, editors. Peer Work in Australia: A New Future for Mental Health. g. a. h ed. Sydney: RichmondPRA and Mind Australia.; 2018. p.\u0026nbsp;d.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFava N, Simmons MB, Anderson R, Zbukvic I, Baker D. Side by side: supporting youth peer work in mental health services. Melbourne: Orygen 2020.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBurke EM, Pyle M, Machin K, Morrison AP. Providing mental health peer support 2: Relationships with empowerment, hope, recovery, quality of life and internalised stigma. Int J Soc Psychiatry. 2018;64(8):745\u0026ndash;55.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGillard S, Gibson SL, Holley J, Lucock M. Developing a change model for peer worker interventions in mental health services: a qualitative research study. Epidemiol Psychiatr Sci. 2015;24(5):435\u0026ndash;45.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGillard S. Peer support in mental health services: where is the research taking us, and do we want to go there? J Ment Health. 2019;28(4):341\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJacob KS. Recovery model of mental illness: a complementary approach to psychiatric care. Indian J Psychol Med. 2015;37(2):117\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJordan G, Grazioplene R, Florence A, Hammer P, Funaro MC, Davidson L, et al. Generativity among persons providing or receiving peer or mutual support: A scoping review. Psychiatr Rehabil J. 2021.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSimmons M. Young people key to improving mental health research. Nature Human Behaviour. 2021.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-psychiatry","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bpsy","sideBox":"Learn more about [BMC Psychiatry](http://bmcpsychiatry.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bpsy/default.aspx","title":"BMC Psychiatry","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-1617867/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1617867/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground\u003c/strong\u003e: Peer support has become increasingly popular in adult mental health services to complement existing care provided by clinicians with formal training. The same is now happening to support young people with anxiety and depression but it is unclear what the evidence base of peer support in this population is.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eA systematic search was conducted with the Orygen Evidence Finder database, Embase, MEDLINE, and PsycInfo from January 1980 to July 2021. Controlled trials of interventions aimed to educate or treat young people (mean age between 14-24) to improve their mental health, which were delivered by a peer worker with lived experienced of mental health challenges were included. Outcomes related to depression or anxiety were extracted. Study quality was rated using the Critical Appraisal Skills Programme.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eEight randomised controlled trials with 1,885\u0026nbsp;participants were included, with six undertaken in high income countries. One targeted depression and anxiety, another targeted stigma-distress in youth mental illness, one aimed at first episode psychosis, four studies for preventing eating disorders and one aimed at drug misuse. One study successfully reduced anxiety and depression, another reduced depression only, four reported reductions in negative affect, with the final two measuring, but not having a significant impact on depression. Study quality was rated as ‘good’ overall.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eDiscussion: \u003c/strong\u003eDespite the uptake of youth peer support globally, there is limited evidence from controlled trials of the effect of peer support related interventions on anxiety and depression. Further rigorously designed trials of peer delivered interventions for young people experiencing anxiety and depression need to be conducted with a focus on understanding the mechanisms of action underpinning peer support. In the absence of sufficient evidence, we propose potential mechanisms to guide future research into how peer support is an active ingredient for youth anxiety and depression.\u0026nbsp;\u003c/p\u003e","manuscriptTitle":"The effectiveness of peer support from a person with lived experience of mental health challenges for young people with anxiety and depression: A systematic review","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-05-20 15:14:56","doi":"10.21203/rs.3.rs-1617867/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2022-06-30T08:05:23+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2022-06-15T11:29:14+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"5e0a3ff0-429b-491b-b889-199c3f31775e","date":"2022-06-12T13:58:39+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"058a7de2-4174-4f42-9918-94fd6ac5bbf5","date":"2022-05-23T17:41:53+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2022-05-22T22:36:42+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2022-05-20T12:02:12+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2022-05-17T11:47:04+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2022-05-17T11:45:28+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Psychiatry","date":"2022-05-03T00:30:16+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-psychiatry","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bpsy","sideBox":"Learn more about [BMC Psychiatry](http://bmcpsychiatry.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bpsy/default.aspx","title":"BMC Psychiatry","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"56b8b326-014a-42dd-b7c8-c2af60cec0f8","owner":[],"postedDate":"May 20th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2023-10-16T20:11:04+00:00","versionOfRecord":{"articleIdentity":"rs-1617867","link":"https://doi.org/10.1186/s12888-023-04578-2","journal":{"identity":"bmc-psychiatry","isVorOnly":false,"title":"BMC Psychiatry"},"publishedOn":"2023-03-24 20:07:09","publishedOnDateReadable":"March 24th, 2023"},"versionCreatedAt":"2022-05-20 15:14:56","video":"","vorDoi":"10.1186/s12888-023-04578-2","vorDoiUrl":"https://doi.org/10.1186/s12888-023-04578-2","workflowStages":[]},"version":"v1","identity":"rs-1617867","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1617867","identity":"rs-1617867","version":["v1"]},"buildId":"FbvkV6FR0MCFSLy54lSbu","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}