The Questionnaire for Psychotic Experiences: Preliminary validation of the Italian version (QPE-I) in a general population sample

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The QPE is a comprehensive, transdiagnostic tool designed to assess psychotic phenomena in the areas of auditory, visual, olfactory, tactile hallucinations, and delusions from a qualitative-quantitative perspective in both general and clinical populations. In this study, a total of 87 adult participants completed the QPE-I along with other self-report measures to determine reliability, internal consistency, and validity. The results indicate that the QPE-I largely retains the core structure of the original instrument while being adapted to the Italian context, showing good cross-cultural adaptation, internal consistency, reliability, and convergent and divergent validity. The QPE-I facilitates the transdiagnostic exploration of psychotic experiences, distinguishing qualitative differences in hallucinations and delusions between individuals. It also has potential clinical applications in psychotherapy, providing a means of monitoring symptomatic change and therapeutic outcomes. Further studies with larger and clinical samples are needed. Background In recent years, in contrast to the categorical approach of the "Kraepelinian dichotomy,"( 1 ) research has increasingly supported the hypothesis of a dimensional approach to psychosis, suggesting a continuum of psychotic experiences between healthy individuals and patients with psychotic and other disorders ( 2 ). Psychotic experiences show a wide range of phenomenological variations ( 3 ), with the most commonly reported being auditory and visual hallucinations and delusions ( 4 ). Other types of hallucinations, such as olfactory and tactile ones, are likely to be under-reported. According to this perspective, psychotic experiences (PEs) can be seen as transdiagnostic phenomena, such as hallucinations and delusions, that can range from subclinical manifestations in the general population to more severe and distressing forms in the psychiatric population ( 5 ) ( 6 ) ( 7 ). The estimated lifetime prevalence of psychotic experiences in the general population is 7.8%, with most people considering these to be transient phenomena, although in some cases, they may be persistent or recurrent ( 5 ). The most common psychiatric diagnoses associated with psychotic experiences include schizophrenia ( 8 ), bipolar disorder, and major depressive disorder ( 9 ), but they also occur in neurological illnesses and medical conditions ( 10 ). In addition, the presence of PEs in depression and anxiety predicts greater psychopathology ( 5 ). Despite this, there is a lack of tools capable of capturing the diverse phenomenological modalities of PEs: most existing ones are limited to assessing a single modality at a time ( 11 ) or only provide global scores that do not account for individual delusional themes or specific hallucination modalities ( 4 ). A recent review of PEs in the general population (2022) clearly states that there is a need for more in-depth analysis of different types of PEs to clarify their potentially divergent trajectories and psychopathological significance and that self-report measures without information on duration, frequency, or conviction risk misidentifying phenomena ( 5 ). To address these gaps in assessing PEs, in 2019, Rossell and Schutte developed a trans-diagnostic tool to explore the diverse and nuanced phenomenology of psychotic experiences from a qualitative-quantitative perspective. The Questionnaire for Psychotic Experiences (QPE) assesses auditory, visual, olfactory, and tactile hallucinations, as well as different types of delusions, with a total of 50 qualitative and quantitative items. Psychotic experiences are assessed as lifetime events and current experiences within the past 7 days. Overall, the QPE allows analyses of the four subscales: auditory hallucinations (AH), visual hallucinations (VH), total hallucinations (TotH), and delusions (D) as well as an overall severity score (total QPE). The original English version demonstrated strong psychometric properties, with Cronbach’s α > 0.7, near-perfect inter-rater reliability (ranging from 0.99 to 1), and excellent test-retest reliability (ranging from 0.70 to 0.92). Psychometric evaluations have been conducted on both clinical and general populations. Convergent validity was assessed by performing interscale correlations between the QPE and the PSYRATS ( 12 ) (AH and delusions subscales), PANSS ( 13 ) (hallucination and delusion items), SAPS ( 14 ) (hallucinations and delusions subscale), and NEVHI ( 15 ) (total VH severity score). PANSS (negative and general subscales), BDI ( 16 ) (total score), and BAI ( 17 ) (total score) were used to assess discriminant validity. As a result, convergent and divergent validity were found to be adequate, supporting the utility of the QPE in assessing psychotic experiences in different contexts ( 4 ). Given the lack of such comprehensive instruments for measuring psychotic experiences in Italy, the aim of this study is to validate the Italian version of the Questionnaire for Psychotic Experiences (QPE-I) and to measure its psychometric properties in a general population sample, paving the way for its use in clinical contexts in our country and support a cross-cultural understanding of the construct as well as promote a broader and more nuanced perspective on psychotic experiences ( 18 ). Methods Participants Participants (N = 87) were recruited from the general population by publicizing the research through social networks. The sample's age ranged from 18 to 60 years, with a mean age of 29.33 years (± 7.3). Inclusion criteria required both a good understanding of the Italian language and the absence of mental retardation. Participants were assessed for a) current use of alcohol, drugs, and medications (categorized as weekly, monthly, every 3–6 months, once a year); b) past use of alcohol, drugs, and medications (categorized as current); c) discontinued use of alcohol, drugs, and medications, with duration of cessation. Demographic information was also collected. All participants gave informed consent before completing the protocol and completed the questionnaires under the investigator's supervision. Two participants were excluded from the study due to issues in finishing the test. The study was approved by the Human Research Ethics Committee of the University of Urbino Carlo Bo. Measures A total of 4 self-report instruments were administered to the participants. The main instrument was the Italian version of the Questionnaire for Psychotic Experiences (QPE-I). Like the original version, the QPE-I comprises 50 qualitative and quantitative items assessing different types of hallucinations and delusions in the lifetime and as current experiences. The scale provides five total scores, including auditory hallucinations (AH), visual hallucinations (VH), total hallucinations (TotH), delusions (D), and overall severity of psychotic experiences (total QPE score). For AH and VH, severity is calculated by summing items rated on a 6-point scale (0–5) on frequency, duration, distress, and impact. D severity is based on conviction, preoccupation, distress, and impact. These scores do not include phenomenological features (e.g., specific descriptive features). To calculate total hallucinations (TotH) and total severity of psychotic experiences (Total QPE score), frequency of tactile hallucinations (THs), frequency of olfactory hallucinations (OHs), frequency of multimodal hallucinations, and frequency of sleep paralysis (SP) were also included. The QPE scores exclude distress and impact information for THs, OHs, multimodal hallucinations, and SP for brevity. In addition to QPE-I, three other self-reports were administered to evaluate the convergent and divergent validity of the scale, together with clinical dimensions in the sample. The Community Assessment of Psychic Experience ( 19 , 20 ) is a 42-item self-report questionnaire used to measure psychotic symptoms and as a screening tool to identify individuals at ultra-high risk for psychosis. It is derived from a combination of the Peters Delusions Inventory (PDI) ( 21 ), modified in the wording of some items with the addition of items from the Scale for the Assessment of Negative Symptoms (SANS) ( 14 ) and the Subjective Experience of Negative Symptoms Scale (SENS) ( 22 ). CAPE provides scores on three dimensions: positive (20 items), negative (14 items), and depressive (8 items). For each item, the frequency is indicated on a four-point Likert scale (never = 1, sometimes = 2, often = 3, always = 4) and, in the case of a positive response (score > 1), the level of discomfort is also assessed on four possible levels: not at all = 1, a little = 2, quite a lot = 3, a lot = 4). For each dimension, it is, therefore, possible to calculate two different total scores: Frequency and Distress. The State-Trait Anxiety Inventory (STAY-X; ( 23 , 24 ) is a 40-item self-report measure of anxiety, rated on a four-point Likert scale (ranging from "not at all" to "very much") and divided into two subscales addressing state anxiety (20 items) and trait anxiety (20 items). STAY showed good internal consistency, with Cronbach's alpha typically ranging from 0.86 to 0.95 for both the state (A-State) and trait (A-Trait) scale and good retest reliability for the trait subscale (ranging from 0.73 to 0.86 over time). The Italian adaptation shows similar properties, with Cronbach's alpha generally above 0.85 for both scales and factor analysis results are consistent with the original scale. The Symptom Checklist-90-Revised ( 25 , 26 ) is administered to investigate the various clinical dimensions within the sample. The SCL-90-R is a 90-item self-report questionnaire designed to assess symptom severity across several clinical dimensions. Each item is rated on a five-point Likert scale ranging from 0 = not at all to 4 = extremely. The questionnaire consists of nine primary dimensions: Somatization (SOM); Obsessive-Compulsivity (O-C); Interpersonal Sensitivity (I-S); Depression (DEP); Anxiety (ANX); Hostility (HOS); Phobic Anxiety (PHOB); Paranoid Ideation (PAR); Psychoticism (PSY). The SCL-90-R can also provide three global indices consisting of the Global Severity Index (GSI), Positive Symptom Total (PST), and Positive Symptom Distress Index (PSDI). The scale is widely used and has strong psychometric properties (Cronbach's alpha > 0.80 on most dimensions). The Italian version retained the nine-factor structure of the original questionnaire and showed strong internal consistency (Cronbach's alpha > 0.85 for most dimensions). Cross-cultural adaptation process of the QPE-I The QPE was translated into Italian according to the guidelines for cross-cultural adaptation of self-report instruments( 27 ). First, two native speakers of the target language (Italian) with different backgrounds (one clinical, the other nonclinical) translated the QPE from English to Italian (forward translation). Working independently, the translators noted ambiguous or problematic phrases and produced two versions: T1 and T2. Secondly, the two translators compared their translations in the presence of an observer to reach a consensus and thus produce a synthesis of the translations: T12. Third, two native speakers of the original language (English) independently translated the T12 version back into English. The translators were blind to the original QPE; they had no theoretical knowledge of what the instrument measured and no background in clinical psychology. They produced two independent versions: BT1 and BT2 (back translations). Fourth, a committee of experts reviewed all the translated versions to achieve semantic, idiomatic, and conceptual equivalence, thus creating a pre-final version (committee review). Finally, the pre-final version was administered to a group of 30 participants (mean age = 28.32), who were invited to leave comments and answers to additional comprehensibility questions (pre-testing). Then, in the final approval phase, after careful consideration of the comments, the final version (QPE-I) was produced, and approval was obtained from the author of the original version. Establishing psychometric properties To assess the psychometric properties of the QPE-I, six principal component analyses (PCA) were conducted to replicate the procedure used in the original study (including the AH, VH, and D subscales, both lifetime and current). For each subscale, all items, 15 each for AH and VH and 5 for D, were included in the analyses. As in the original study, promax rotations were used, considering the ordinal nature of the items and the expected correlations between them. Eigenvalues greater than one and factor loadings greater than 0.4 were retained and considered satisfactory. For convergent validity, correlations were performed with the two positive subscales of the CAPE (Frequency and Distress), which were predicted to show a significant positive correlation. The SCL-90-R paranoid ideation subscale was expected to show a positive correlation with the QPE-I delusions subscales (current and lifetime), and the psychoticism subscale was expected to show a positive correlation with the QPE-I total. For discriminant validity, we used STAY-X, which was not expected to show a significant strong correlation with the QPE-I (at P .55). Internal consistency was assessed for each subscale and dimension using Cronbach's alpha. Cronbach's alpha values > .70 were considered acceptable. Interscale correlations were conducted with the expectation that they would be low and nonsignificant between subscales (i.e., AH, VH, and D), while individual subscales were expected to correlate with the total. Results Cross-cultural adaptation process No significant disagreements or problems arose during the cross-cultural adaptation process. Only one issue arose after an exchange with the authors: they informed us of the existence of a second, newer, but longer version of the test (more detailed in the delusions section) in addition to the original version developed two years earlier. After extensive analysis of the second version, it was decided to continue with the validation of the original version, as it was considered easier to administer to a wide range of people, from healthy to patients with psychotic and other disorders in our mental health services. Descriptive analyses Descriptive analyses are presented in Tables 1 and 2. 19.5% of the sample have a history of substance use, and 9.2% of the sample are current users. In addition, 47.1% of the sample used alcohol, including 53.2% weekly. The SCL-90-R Depression subscale was the clinical dimension most represented in the sample (27.6%), followed by OCD (26.4%). Factor analysis Our study partially confirmed the original structure. The three-factor model was confirmed for the AH subscales (current and lifetime) and (VH lifetime), as well as a one-factor model for the D subscales (current and lifetime). The VH current subscale showed a better fit with a two-factor model. For the current AH subscale, current experience analyses yielded the following dimensions: level of functioning, pervasiveness, and impact. These factors accounted for 87% of the variance. The lifetime AH subscale is composed of the same dimensions, and these factors accounted for 85% of the variance. In this case, the item "frequency" did not load on any of the 3 factors. The current VH subscale was found to be composed of the following dimensions: level of functioning and impact, and these factors accounted for 85% of the variance. For the Lifetime VH subscale, past experience analyses yielded the following dimensions: level of functioning, pervasiveness, passage, which accounted for 87% of the variance. In this case, the item "illusions" did not load clearly on any of the 3 factors, indicating a complex structure. When considering the D subscales, the unidimensional model was labeled Impact on Functioning, as in the original study. It accounted for 60% of the variance in the current data and 49% of the variance in the lifetime data. Table 3 shows the extended results. Convergent and divergent validity Table 4 shows the convergent and divergent validity. The results confirm our previous hypothesis, except for the lack of correlation between the CAPE positive subscale and the VH lifetime subscale. In addition, the SCL-90-R Psychoticism subscale shows a strong correlation with the Delusions Lifetime subscale. Reliability Reliability data are presented in Table 5, showing internal consistency and interscale correlations. The QPE-I subscales showed internal consistency ranging from excellent to good, with Cronbach's α ranging from .73 to .93 for lifetime experiences and 0.72 to 0.96 for current experiences. The TotH is an exception, showing just acceptable internal consistency with Cronbach's α of .62 and .69 for lifetime and current experiences, respectively. In this scale, the item-total correlations for certain items appear to be low, as in the case of O1 (.063) and O3 (.067) for lifetime experiences and A3 (.185), O1 (.126) for current experiences. The QPE-I scale also shows some low item-total correlations, as observed in the case of O1 (.167) and O3 (.067) for lifetime experiences and A3 (.065), A6 (.091) for current experiences. The interscale correlations were mostly low and no significant across the subscales (i.e., AH, VH, and D), except AH with D in lifetime experiences, which was already significant in the original study. Individual subscales were correlated with total subscale scores (i.e., AH with TotH and QPE). Overall, these data indicate good internal consistency, especially for the AH, VH, and D subscales and for the assessment of different dimensions of psychotic experiences. Discussion The aim of this study was to validate the Italian version of the Questionnaire for Psychotic Experiences (QPE-I) and to measure its psychometric properties in a general population sample. The QPE-I was able to collect data on a wide range of psychotic experiences in participants selected from the general population and unlikely to be familiar to health professionals. As in the original study, auditory hallucinations were the most commonly reported phenomenon ( 4 ). Rates of delusional ideation, but not of delusions, were high, likely reflecting the non-clinical nature of the sample ( 6 ). Olfactory and tactile hallucinations were present, with olfactory hallucinations showing even higher rates than visual hallucinations, although this phenomenon is usually overlooked in the literature ( 28 ). Statistical analysis revealed strong psychometric properties for the QPE-I. Our data show that the interview measures different dimensions of psychotic experiences, with good internal consistency and a good ability to discriminate psychotic experiences from other psychological phenomena. The total hallucinations subscale (TotH) was the only one that did not show high internal consistency (Cronbach's α of .62 and .69 for lifetime and current experiences, respectively), with low item-total correlations, especially for items measuring “other” hallucinations, which in fact have less space in the interview. It will be useful to replicate these data in a clinical sample and examine these items and the scales that contain them. The structural analysis of the QPE-I didn’t exactly match that of the original interview. Our study confirms the original with a three-factor structure for the auditory hallucinations (AH) subscales and the visual hallucinations (VH) lifetime subscale and a one-factor model for the delusions (D) subscales. The VH current subscale was the only exception, showing a better fit with a two-factor model, including the level of functioning and impact, whereas the original study found three dimensions (impact on functioning, incidence, and illusions). In addition, the underlying dimensions of the other subscales do not fully overlap. While both studies found a 3-factor solution for the AH subscales, the specific dimensions underlying the subscales differed. For the current subscale, "incidence" and "illusions" in the original study are replaced by "pervasiveness" and "impact" in our study. The same happens with the “insight" and "illusions" dimensions in the lifetime subscale. Moreover, the variance explained is significantly higher in the QPE-I version (63% in the original study, 87% in our study for current, 49% vs. 85% for lifetime). The lack of clinical representation in the sample may have led to a redefinition of the dimensions and differences in factor interpretation, translation nuances, or cultural differences in item perception. Therefore, it is important to continue to study the psychometric properties of the QPE-I in a clinical sample to compare results. The results for delusions are consistent between the two studies, supporting the robustness of the unidimensional structure across cultures. Several limitations of the current study should be noted. First, the sample should be increased to maintain statistical power, especially considering that PCA with Promax rotation, whether useful for capturing complex structures, requires a larger sample size. Second, as already said, testing the interview on a clinical sample will be important to assess how it works transdiagnostically. Finally, this study inherits the limitations of the original research, including the need to validate psychometric properties in neurological and medical disorder samples and to conduct thorough test-retest reliability and inter-rater agreement assessments. Conclusions The Italian version of the Questionnaire for Psychotic Experiences (QPE-I) is proving to be a valuable tool for assessing psychotic experiences in both general and clinical contexts in Italy. It provides a detailed picture of both qualitative and quantitative aspects of psychotic phenomena, offering valuable insights into the nuanced dimensions of these experiences. This makes it particularly useful for transdiagnostic assessment, examining qualitative differences in psychotic experiences among individuals with different psychiatric disorders, such as schizophrenia and borderline personality disorder, where the phenomenological quality of the experience rather than its quantity is crucial for a deeper understanding. In addition to its utility in clinical diagnosis and differentiation, the QPE-I has demonstrated its applicability to non-clinical populations, providing insight into common, often overlooked symptoms. The QPE-I could be very useful for application in psychotherapy settings, allowing clinicians to monitor symptomatology improvements over therapeutic interventions, providing a structured framework for assessing changes in the phenomenology of psychotic symptoms and providing an outcome measure for intervention research. Further studies with a larger sample, mixing clinical and non-clinical participants, are needed to confirm and extend the psychometric properties of the QPE-I and to ensure its robustness and applicability across different populations. Nonetheless, the QPE-I stands as a useful tool that significantly enriches the understanding and assessment of psychotic experiences in our country. Abbreviations QPE Questionnaire for Psychotic Experiences QPE I-Italian version of the Questionnaire for Psychotic Experiences AH Auditory Hallucinations VH Visual Hallucinations TotH Total Hallucinations D Delusions PANSS Positive and Negative Syndrome Scale PSYRATS Psychotic Symptom Rating Scales SAPS Scale for the Assessment of Positive Symptoms NEVHI North East Visual Hallucinations Interview BDI Beck Depression Inventory BAI Beck Anxiety Inventory CAPE Community Assessment of Psychic Experience PDI Peters Delusions Inventory SANS Scale for the Assessment of Negative Symptoms SENS Subjective Experience of Negative Symptoms Scale STAY X-State-Trait Anxiety Inventory SCL 90-R-Symptom Checklist-90-Revised SOM Somatization O C-Obsessive-Compulsivity I S-Interpersonal Sensitivity DEP Depression ANX Anxiety HOS Hostility PHOB Phobic Anxiety PAR Paranoid Ideation PSY Psychoticism GSI Global Severity Index PST Positive Symptom Total PSDI Positive Symptom Distress Index SP Sleep Paralysis Declarations Ethics approval and consent to participate: This study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki. Ethical approval for the study was obtained from the Ethics Committee for Human Experimentation (CESU) of the University of Urbino Carlo Bo . The committee reviewed and approved the study protocol, ensuring compliance with ethical standards for research involving human participants. All participants provided informed consent prior to their inclusion in the study. They were fully informed about the purpose, procedures, potential risks, and benefits of the research. Participation was voluntary, and participants were free to withdraw from the study at any time without any consequences. Confidentiality and data protection were maintained in accordance with applicable regulations. Clinical trial number: not applicable. Consent for publication: does not applies. 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: Does not applies (no funding). Authors' contributions: CG conceptualized the study and conducted data collection; MM assisted with data collection and performed data analysis; AQ supported the data analysis; AA supervised the entire project. All authors contributed to drafting the manuscript. Acknowledgements: Does not applies. References Kraepelin E. Manic Depressive Insanity and Paranoia: J Nerv Ment Dis. 1921 Apr;53(4):350. Hinterbuchinger B, Mossaheb N. Psychotic-Like Experiences: A Challenge in Definition and Assessment. Front Psychiatry. 2021 Mar 29;12:582392. Armando M, Nelson B, Yung AR, Saba R, Monducci E, Dario C, et al. Psychotic experience subtypes, poor mental health status and help‐seeking behaviour in a community sample of young adults. Early Interv Psychiatry. 2012 Aug;6(3):300–8. Rossell SL, Schutte MJL, Toh WL, Thomas N, Strauss C, Linszen MMJ, et al. The Questionnaire for Psychotic Experiences: An Examination of the Validity and Reliability. Schizophr Bull. 2019 Feb 1;45(Supplement_1):S78–87. Staines L, Healy C, Coughlan H, Clarke M, Kelleher I, Cotter D, et al. Psychotic experiences in the general population, a review; definition, risk factors, outcomes and interventions. Psychol Med. 2022 Nov;52(15):3297–308. Bebbington P, Freeman D. Transdiagnostic Extension of Delusions: Schizophrenia and Beyond. Schizophr Bull. 2017 Mar 1;43(2):273–82. Sommer IE, Koops S, Blom JD. Comparison of auditory hallucinations across different disorders and syndromes. Neuropsychiatry. 2012;1–12. Merrett Z, Rossell SL, Castle DJ. Comparing the experience of voices in borderline personality disorder with the experience of voices in a psychotic disorder: A systematic review. Aust N Z J Psychiatry. 2016 Jul;50(7):640–8. Toh WL, Thomas N, Rossell SL. Auditory verbal hallucinations in bipolar disorder (BD) and major depressive disorder (MDD): A systematic review. J Affect Disord. 2015 Sep;184:18–28. Sommer IE, Koops S, Blom JD. Comparison of auditory hallucinations across different disorders and syndromes. Neuropsychiatry. 2012 Feb;2(1):57–68. Lee K, Chan K, Chang W, Lee EH, Hui CL, Chen EY. A systematic review on definitions and assessments of psychotic‐like experiences. Early Interv Psychiatry. 2016 Feb;10(1):3–16. Haddock G, McCARRON J, Tarrier N, Faragher EB. Scales to measure dimensions of hallucinations and delusions: the psychotic symptom rating scales (PSYRATS). Psychol Med. 1999 Jul;29(4):879–89. Kay SR, Fiszbein A, Opler LA. The Positive and Negative Syndrome Scale (PANSS) for Schizophrenia. Schizophr Bull. 1987 Jan 1;13(2):261–76. Andreasen NC. The Scale for the Assessment of Negative Symptoms (SANS): Conceptual and Theoretical Foundations. Br J Psychiatry. 1989 Nov;155(S7):49–52. Mosimann UP, Collerton D, Dudley R, Meyer TD, Graham G, Dean JL, et al. A semi‐structured interview to assess visual hallucinations in older people. Int J Geriatr Psychiatry. 2008 Jul;23(7):712–8. Beck AT. An Inventory for Measuring Depression. Arch Gen Psychiatry. 1961 Jun 1;4(6):561. Beck AT, Epstein N, Brown G, Steer RA. An inventory for measuring clinical anxiety: Psychometric properties. J Consult Clin Psychol. 1988;56(6):893–7. Yehya A, Khaled SM, Sommer IEC, Elhag SF, Hassan MHMO, Woodruff P, et al. The Arabic Questionnaire for Psychotic Experiences in patients with psychotic disorders: a clinical validation. BMC Psychiatry. 2023 Mar 7;23(1):141. Daneluzzo E, Tommaso SD, Tempesta D, Cerroni G, Stratta P, Rossi A. The Community Assessment Psychic Experience (CAPE): evaluation study of the Italian version. Epidemiol Psichiatr Soc. 2008 Sep;17(3):242–7. Stefanis NC, Hanssen M, Smirnis NK, Avramopoulos DA, Evdokimidis IK, Stefanis CN, et al. Evidence that three dimensions of psychosis have a distribution in the general population. Psychol Med. 2002 Feb;32(2):347–58. Peters ER, Joseph SA, Garety PA. Measurement of Delusional Ideation in the Normal Population: Introducing the PDI (Peters et al. Delusions Inventory). Schizophr Bull. 1999 Jan 1;25(3):553–76. Selten JP, Gernaat HBPE, Nolen WA, Wiersma D, Van Den Bosch RJ. Experience of Negative Symptoms: Comparison of Schizophrenic Patients to Patients With a Depressive Disorder and to Normal Subjects. Am J Psychiatry. 1998 Mar 1;155(3):350–4. Lazzari R, Pancheri P. Questionario di Valutazione dell’Ansia di Stato e di Tratto (State-Trait Anxiety Inventory). Organizzazioni Speciali, Firenze. 1980; Spielberger CD, Gorsuch RL, Lushene R, Vagg PR, Jacobs GA. Manual for the State-Trait Anxiety Inventory. Consulting Psychologists Press. Palo Alto, CA; 1983. Prunas A, Sarno I, Preti E, Madeddu F, Perugini M. Psychometric properties of the Italian version of the SCL-90-R: A study on a large community sample. Eur Psychiatry. 2012 Nov;27(8):591–7. Todd DM, Deane FP, McKenna PA. Appropriateness of SCL-90-R adolescent and adult norms for outpatient and nonpatient college students. J Couns Psychol. 1997 Jul;44(3):294–301. Beaton DE, Bombardier C, Guillemin F, Ferraz MB. Guidelines for the Process of Cross-Cultural Adaptation of Self-Report Measures. Spine. 2000;25(24):3186–91. Langdon R, McGuire J, Stevenson R, Catts SV. Clinical correlates of olfactory hallucinations in schizophrenia. Br J Clin Psychol. 2011 Jun;50(2):145–63. Tables Tables 1 to 5 are available in the Supplementary Files section Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6194339","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":433208389,"identity":"d561a627-b8fd-473c-baa7-63c92ba14683","order_by":0,"name":"Chiara Gagliardi","email":"","orcid":"","institution":"University of Urbino","correspondingAuthor":false,"prefix":"","firstName":"Chiara","middleName":"","lastName":"Gagliardi","suffix":""},{"id":433208390,"identity":"cd0223f8-8dca-4031-95e0-7b3752ef8d17","order_by":1,"name":"Marta Moselli","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA5ElEQVRIiWNgGAWjYHAD5sYDCRUMDGxgZIBXKWMDjD6QcAauBa8eJC2MbWAWUAsea3Tbzz5/8INhm5x8e2PDgYfzDufxSeQ+e8BQ8AenFrMz6YaNPQy3jQ3OHGw4kLjtcDGbRLq5AT6HmR1IY2zgYbiduEEiEawlsU0ijU0Cr5bzzxgb/wC1zJ//EKhlDjFabqQxNoNsabgB9H5iA1FanjHOljEA+QXosIRj6YltPM/YDRIMjPE4LI3h45uK28AQO3zw4Y8a68T57WlsDz78kcOpBQIwXJFAQMMoGAWjYBSMAvwAAEh4WIbJ/rvuAAAAAElFTkSuQmCC","orcid":"","institution":"University of Urbino","correspondingAuthor":true,"prefix":"","firstName":"Marta","middleName":"","lastName":"Moselli","suffix":""},{"id":433208391,"identity":"bef6945a-afe3-4ae2-b839-2b95ed28ef95","order_by":2,"name":"Arianna Quassoni","email":"","orcid":"","institution":"University of Urbino","correspondingAuthor":false,"prefix":"","firstName":"Arianna","middleName":"","lastName":"Quassoni","suffix":""},{"id":433208392,"identity":"8c4e79bb-aa87-4deb-b9ed-b45cb3cacc16","order_by":3,"name":"Alessandra D'Agostino","email":"","orcid":"","institution":"University of Urbino","correspondingAuthor":false,"prefix":"","firstName":"Alessandra","middleName":"","lastName":"D'Agostino","suffix":""}],"badges":[],"createdAt":"2025-03-10 10:08:31","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6194339/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6194339/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":83976990,"identity":"7876f047-fb78-49ba-b70d-fefa7a306a04","added_by":"auto","created_at":"2025-06-05 09:09:04","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":492812,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6194339/v1/8b166159-6dc9-48a0-81c4-63f24238ce4a.pdf"},{"id":79181165,"identity":"082e8ccb-7e76-4fbc-a777-04d0acbfaf59","added_by":"auto","created_at":"2025-03-25 10:31:45","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":31537,"visible":true,"origin":"","legend":"","description":"","filename":"Tables.docx","url":"https://assets-eu.researchsquare.com/files/rs-6194339/v1/b92095ebe8e2287e9dd3cc0a.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Questionnaire for Psychotic Experiences: Preliminary validation of the Italian version (QPE-I) in a general population sample","fulltext":[{"header":"Background","content":"\u003cp\u003eIn recent years, in contrast to the categorical approach of the \"Kraepelinian dichotomy,\"(\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) research has increasingly supported the hypothesis of a dimensional approach to psychosis, suggesting a continuum of psychotic experiences between healthy individuals and patients with psychotic and other disorders (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e). Psychotic experiences show a wide range of phenomenological variations (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e), with the most commonly reported being auditory and visual hallucinations and delusions (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Other types of hallucinations, such as olfactory and tactile ones, are likely to be under-reported.\u003c/p\u003e \u003cp\u003eAccording to this perspective, psychotic experiences (PEs) can be seen as transdiagnostic phenomena, such as hallucinations and delusions, that can range from subclinical manifestations in the general population to more severe and distressing forms in the psychiatric population (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e) (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e) (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e). The estimated lifetime prevalence of psychotic experiences in the general population is 7.8%, with most people considering these to be transient phenomena, although in some cases, they may be persistent or recurrent (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). The most common psychiatric diagnoses associated with psychotic experiences include schizophrenia (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e), bipolar disorder, and major depressive disorder (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e), but they also occur in neurological illnesses and medical conditions (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). In addition, the presence of PEs in depression and anxiety predicts greater psychopathology (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eDespite this, there is a lack of tools capable of capturing the diverse phenomenological modalities of PEs: most existing ones are limited to assessing a single modality at a time (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e) or only provide global scores that do not account for individual delusional themes or specific hallucination modalities (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). A recent review of PEs in the general population (2022) clearly states that there is a need for more in-depth analysis of different types of PEs to clarify their potentially divergent trajectories and psychopathological significance and that self-report measures without information on duration, frequency, or conviction risk misidentifying phenomena (\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eTo address these gaps in assessing PEs, in 2019, Rossell and Schutte developed a trans-diagnostic tool to explore the diverse and nuanced phenomenology of psychotic experiences from a qualitative-quantitative perspective. The Questionnaire for Psychotic Experiences (QPE) assesses auditory, visual, olfactory, and tactile hallucinations, as well as different types of delusions, with a total of 50 qualitative and quantitative items. Psychotic experiences are assessed as lifetime events and current experiences within the past 7 days. Overall, the QPE allows analyses of the four subscales: auditory hallucinations (AH), visual hallucinations (VH), total hallucinations (TotH), and delusions (D) as well as an overall severity score (total QPE).\u003c/p\u003e \u003cp\u003eThe original English version demonstrated strong psychometric properties, with Cronbach\u0026rsquo;s α\u0026thinsp;\u0026gt;\u0026thinsp;0.7, near-perfect inter-rater reliability (ranging from 0.99 to 1), and excellent test-retest reliability (ranging from 0.70 to 0.92). Psychometric evaluations have been conducted on both clinical and general populations. Convergent validity was assessed by performing interscale correlations between the QPE and the PSYRATS (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e) (AH and delusions subscales), PANSS (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e) (hallucination and delusion items), SAPS (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e) (hallucinations and delusions subscale), and NEVHI (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e) (total VH severity score). PANSS (negative and general subscales), BDI (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e) (total score), and BAI (\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e) (total score) were used to assess discriminant validity. As a result, convergent and divergent validity were found to be adequate, supporting the utility of the QPE in assessing psychotic experiences in different contexts (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eGiven the lack of such comprehensive instruments for measuring psychotic experiences in Italy, the aim of this study is to validate the Italian version of the Questionnaire for Psychotic Experiences (QPE-I) and to measure its psychometric properties in a general population sample, paving the way for its use in clinical contexts in our country and support a cross-cultural understanding of the construct as well as promote a broader and more nuanced perspective on psychotic experiences (\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e).\u003c/p\u003e"},{"header":"Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eParticipants\u003c/h2\u003e \u003cp\u003eParticipants (N\u0026thinsp;=\u0026thinsp;87) were recruited from the general population by publicizing the research through social networks. The sample's age ranged from 18 to 60 years, with a mean age of 29.33 years (\u0026plusmn;\u0026thinsp;7.3). Inclusion criteria required both a good understanding of the Italian language and the absence of mental retardation. Participants were assessed for a) current use of alcohol, drugs, and medications (categorized as weekly, monthly, every 3\u0026ndash;6 months, once a year); b) past use of alcohol, drugs, and medications (categorized as current); c) discontinued use of alcohol, drugs, and medications, with duration of cessation. Demographic information was also collected.\u003c/p\u003e \u003cp\u003e All participants gave informed consent before completing the protocol and completed the questionnaires under the investigator's supervision. Two participants were excluded from the study due to issues in finishing the test. The study was approved by the Human Research Ethics Committee of the University of Urbino Carlo Bo.\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003eMeasures\u003c/h3\u003e\n\u003cp\u003eA total of 4 self-report instruments were administered to the participants.\u003c/p\u003e \u003cp\u003eThe main instrument was the \u003cem\u003eItalian version of the Questionnaire for Psychotic Experiences\u003c/em\u003e (QPE-I). Like the original version, the QPE-I comprises 50 qualitative and quantitative items assessing different types of hallucinations and delusions in the lifetime and as current experiences. The scale provides five total scores, including auditory hallucinations (AH), visual hallucinations (VH), total hallucinations (TotH), delusions (D), and overall severity of psychotic experiences (total QPE score). For AH and VH, severity is calculated by summing items rated on a 6-point scale (0\u0026ndash;5) on frequency, duration, distress, and impact. D severity is based on conviction, preoccupation, distress, and impact. These scores do not include phenomenological features (e.g., specific descriptive features). To calculate total hallucinations (TotH) and total severity of psychotic experiences (Total QPE score), frequency of tactile hallucinations (THs), frequency of olfactory hallucinations (OHs), frequency of multimodal hallucinations, and frequency of sleep paralysis (SP) were also included. The QPE scores exclude distress and impact information for THs, OHs, multimodal hallucinations, and SP for brevity.\u003c/p\u003e \u003cp\u003eIn addition to QPE-I, three other self-reports were administered to evaluate the convergent and divergent validity of the scale, together with clinical dimensions in the sample. The \u003cem\u003eCommunity Assessment of Psychic Experience\u003c/em\u003e (\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e) is a 42-item self-report questionnaire used to measure psychotic symptoms and as a screening tool to identify individuals at ultra-high risk for psychosis. It is derived from a combination of the Peters Delusions Inventory (PDI) (\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e), modified in the wording of some items with the addition of items from the Scale for the Assessment of Negative Symptoms (SANS) (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e) and the Subjective Experience of Negative Symptoms Scale (SENS) (\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e). CAPE provides scores on three dimensions: positive (20 items), negative (14 items), and depressive (8 items). For each item, the frequency is indicated on a four-point Likert scale (never\u0026thinsp;=\u0026thinsp;1, sometimes\u0026thinsp;=\u0026thinsp;2, often\u0026thinsp;=\u0026thinsp;3, always\u0026thinsp;=\u0026thinsp;4) and, in the case of a positive response (score\u0026thinsp;\u0026gt;\u0026thinsp;1), the level of discomfort is also assessed on four possible levels: not at all =\u0026thinsp;1, a little\u0026thinsp;=\u0026thinsp;2, quite a lot\u0026thinsp;=\u0026thinsp;3, a lot\u0026thinsp;=\u0026thinsp;4). For each dimension, it is, therefore, possible to calculate two different total scores: Frequency and Distress.\u003c/p\u003e \u003cp\u003eThe \u003cem\u003eState-Trait Anxiety Inventory\u003c/em\u003e (STAY-X; (\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e) is a 40-item self-report measure of anxiety, rated on a four-point Likert scale (ranging from \"not at all\" to \"very much\") and divided into two subscales addressing state anxiety (20 items) and trait anxiety (20 items). STAY showed good internal consistency, with Cronbach's alpha typically ranging from 0.86 to 0.95 for both the state (A-State) and trait (A-Trait) scale and good retest reliability for the trait subscale (ranging from 0.73 to 0.86 over time). The Italian adaptation shows similar properties, with Cronbach's alpha generally above 0.85 for both scales and factor analysis results are consistent with the original scale.\u003c/p\u003e \u003cp\u003eThe \u003cem\u003eSymptom Checklist-90-Revised\u003c/em\u003e (\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e) is administered to investigate the various clinical dimensions within the sample. The SCL-90-R is a 90-item self-report questionnaire designed to assess symptom severity across several clinical dimensions. Each item is rated on a five-point Likert scale ranging from 0\u0026thinsp;=\u0026thinsp;not at all to 4\u0026thinsp;=\u0026thinsp;extremely. The questionnaire consists of nine primary dimensions: Somatization (SOM); Obsessive-Compulsivity (O-C); Interpersonal Sensitivity (I-S); Depression (DEP); Anxiety (ANX); Hostility (HOS); Phobic Anxiety (PHOB); Paranoid Ideation (PAR); Psychoticism (PSY). The SCL-90-R can also provide three global indices consisting of the Global Severity Index (GSI), Positive Symptom Total (PST), and Positive Symptom Distress Index (PSDI). The scale is widely used and has strong psychometric properties (Cronbach's alpha\u0026thinsp;\u0026gt;\u0026thinsp;0.80 on most dimensions). The Italian version retained the nine-factor structure of the original questionnaire and showed strong internal consistency (Cronbach's alpha\u0026thinsp;\u0026gt;\u0026thinsp;0.85 for most dimensions).\u003c/p\u003e\n\u003ch3\u003eCross-cultural adaptation process of the QPE-I\u003c/h3\u003e\n\u003cp\u003eThe QPE was translated into Italian according to the guidelines for cross-cultural adaptation of self-report instruments(\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e). First, two native speakers of the target language (Italian) with different backgrounds (one clinical, the other nonclinical) translated the QPE from English to Italian (forward translation). Working independently, the translators noted ambiguous or problematic phrases and produced two versions: T1 and T2. Secondly, the two translators compared their translations in the presence of an observer to reach a consensus and thus produce a synthesis of the translations: T12. Third, two native speakers of the original language (English) independently translated the T12 version back into English. The translators were blind to the original QPE; they had no theoretical knowledge of what the instrument measured and no background in clinical psychology. They produced two independent versions: BT1 and BT2 (back translations). Fourth, a committee of experts reviewed all the translated versions to achieve semantic, idiomatic, and conceptual equivalence, thus creating a pre-final version (committee review). Finally, the pre-final version was administered to a group of 30 participants (mean age\u0026thinsp;=\u0026thinsp;28.32), who were invited to leave comments and answers to additional comprehensibility questions (pre-testing). Then, in the final approval phase, after careful consideration of the comments, the final version (QPE-I) was produced, and approval was obtained from the author of the original version.\u003c/p\u003e\n\u003ch3\u003eEstablishing psychometric properties\u003c/h3\u003e\n\u003cp\u003eTo assess the psychometric properties of the QPE-I, six principal component analyses (PCA) were conducted to replicate the procedure used in the original study (including the AH, VH, and D subscales, both lifetime and current). For each subscale, all items, 15 each for AH and VH and 5 for D, were included in the analyses. As in the original study, promax rotations were used, considering the ordinal nature of the items and the expected correlations between them. Eigenvalues greater than one and factor loadings greater than 0.4 were retained and considered satisfactory.\u003c/p\u003e \u003cp\u003eFor convergent validity, correlations were performed with the two positive subscales of the CAPE (Frequency and Distress), which were predicted to show a significant positive correlation. The SCL-90-R paranoid ideation subscale was expected to show a positive correlation with the QPE-I delusions subscales (current and lifetime), and the psychoticism subscale was expected to show a positive correlation with the QPE-I total.\u003c/p\u003e \u003cp\u003eFor discriminant validity, we used STAY-X, which was not expected to show a significant strong correlation with the QPE-I (at P\u0026thinsp;\u0026lt;\u0026thinsp;.001 with r\u0026thinsp;\u0026gt;\u0026thinsp;.55). Internal consistency was assessed for each subscale and dimension using Cronbach's alpha. Cronbach's alpha values\u0026thinsp;\u0026gt;\u0026thinsp;.70 were considered acceptable. Interscale correlations were conducted with the expectation that they would be low and nonsignificant between subscales (i.e., AH, VH, and D), while individual subscales were expected to correlate with the total.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cem\u003eCross-cultural adaptation process\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eNo significant disagreements or problems arose during the cross-cultural adaptation process. Only one issue arose after an exchange with the authors: they informed us of the existence of a second, newer, but longer version of the test (more detailed in the delusions section) in addition to the original version developed two years earlier. After extensive analysis of the second version, it was decided to continue with the validation of the original version, as it was considered easier to administer to a wide range of people, from healthy to patients with psychotic and other disorders in our mental health services.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eDescriptive analyses\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eDescriptive analyses are presented in Tables 1 and 2. 19.5% of the sample have a history of substance use, and 9.2% of the sample are current users. In addition, 47.1% of the sample used alcohol, including 53.2% weekly. The SCL-90-R Depression subscale was the clinical dimension most represented in the sample (27.6%), followed by OCD (26.4%).\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eFactor analysis\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eOur study partially confirmed the original structure. The three-factor model was confirmed for the AH subscales (current and lifetime) and (VH lifetime), as well as a one-factor model for the D subscales (current and lifetime). The VH current subscale showed a better fit with a two-factor model. For the current AH subscale, current experience analyses yielded the following dimensions: level of functioning, pervasiveness, and impact. These factors accounted for 87% of the variance. The lifetime AH subscale is composed of the same dimensions, and these factors accounted for 85% of the variance. In this case, the item \"frequency\" did not load on any of the 3 factors. The current VH subscale was found to be composed of the following dimensions: level of functioning and impact, and these factors accounted for 85% of the variance. For the Lifetime VH subscale, past experience analyses yielded the following dimensions: level of functioning, pervasiveness, passage, which accounted for 87% of the variance. In this case, the item \"illusions\" did not load clearly on any of the 3 factors, indicating a complex structure. When considering the D subscales, the unidimensional model was labeled Impact on Functioning, as in the original study. It accounted for 60% of the variance in the current data and 49% of the variance in the lifetime data. Table 3 shows the extended results.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eConvergent and divergent validity\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eTable 4 shows the convergent and divergent validity. The results confirm our previous hypothesis, except for the lack of correlation between the CAPE positive subscale and the VH lifetime subscale. In addition, the SCL-90-R Psychoticism subscale shows a strong correlation with the Delusions Lifetime subscale.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eReliability\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eReliability data are presented in Table 5, showing internal consistency and interscale correlations. The QPE-I subscales showed internal consistency ranging from excellent to good, with Cronbach's α ranging from .73 to .93 for lifetime experiences and 0.72 to 0.96 for current experiences. The TotH is an exception, showing just acceptable internal consistency with Cronbach's α of .62 and .69 for lifetime and current experiences, respectively. In this scale, the item-total correlations for certain items appear to be low, as in the case of O1 (.063) and O3 (.067) for lifetime experiences and A3 (.185), O1 (.126) for current experiences.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe QPE-I scale also shows some low item-total correlations, as observed in the case of O1 (.167) and O3 (.067) for lifetime experiences and A3 (.065), A6 (.091) for current experiences. The interscale correlations were mostly low and no significant across the subscales (i.e., AH, VH, and D), except AH with D in lifetime experiences, which was already significant in the original study. Individual subscales were correlated with total subscale scores (i.e., AH with TotH and QPE). Overall, these data indicate good internal consistency, especially for the AH, VH, and D subscales and for the assessment of different dimensions of psychotic experiences.\u0026nbsp;\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThe aim of this study was to validate the Italian version of the Questionnaire for Psychotic Experiences (QPE-I) and to measure its psychometric properties in a general population sample. The QPE-I was able to collect data on a wide range of psychotic experiences in participants selected from the general population and unlikely to be familiar to health professionals. As in the original study, auditory hallucinations were the most commonly reported phenomenon (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e). Rates of delusional ideation, but not of delusions, were high, likely reflecting the non-clinical nature of the sample (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Olfactory and tactile hallucinations were present, with olfactory hallucinations showing even higher rates than visual hallucinations, although this phenomenon is usually overlooked in the literature (\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eStatistical analysis revealed strong psychometric properties for the QPE-I. Our data show that the interview measures different dimensions of psychotic experiences, with good internal consistency and a good ability to discriminate psychotic experiences from other psychological phenomena. The total hallucinations subscale (TotH) was the only one that did not show high internal consistency (Cronbach's α of .62 and .69 for lifetime and current experiences, respectively), with low item-total correlations, especially for items measuring \u0026ldquo;other\u0026rdquo; hallucinations, which in fact have less space in the interview. It will be useful to replicate these data in a clinical sample and examine these items and the scales that contain them.\u003c/p\u003e \u003cp\u003eThe structural analysis of the QPE-I didn\u0026rsquo;t exactly match that of the original interview. Our study confirms the original with a three-factor structure for the auditory hallucinations (AH) subscales and the visual hallucinations (VH) lifetime subscale and a one-factor model for the delusions (D) subscales. The VH current subscale was the only exception, showing a better fit with a two-factor model, including the level of functioning and impact, whereas the original study found three dimensions (impact on functioning, incidence, and illusions). In addition, the underlying dimensions of the other subscales do not fully overlap. While both studies found a 3-factor solution for the AH subscales, the specific dimensions underlying the subscales differed. For the current subscale, \"incidence\" and \"illusions\" in the original study are replaced by \"pervasiveness\" and \"impact\" in our study. The same happens with the \u0026ldquo;insight\" and \"illusions\" dimensions in the lifetime subscale. Moreover, the variance explained is significantly higher in the QPE-I version (63% in the original study, 87% in our study for current, 49% vs. 85% for lifetime). The lack of clinical representation in the sample may have led to a redefinition of the dimensions and differences in factor interpretation, translation nuances, or cultural differences in item perception. Therefore, it is important to continue to study the psychometric properties of the QPE-I in a clinical sample to compare results.\u003c/p\u003e \u003cp\u003eThe results for delusions are consistent between the two studies, supporting the robustness of the unidimensional structure across cultures.\u003c/p\u003e \u003cp\u003eSeveral limitations of the current study should be noted. First, the sample should be increased to maintain statistical power, especially considering that PCA with Promax rotation, whether useful for capturing complex structures, requires a larger sample size. Second, as already said, testing the interview on a clinical sample will be important to assess how it works transdiagnostically. Finally, this study inherits the limitations of the original research, including the need to validate psychometric properties in neurological and medical disorder samples and to conduct thorough test-retest reliability and inter-rater agreement assessments.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eThe Italian version of the Questionnaire for Psychotic Experiences (QPE-I) is proving to be a valuable tool for assessing psychotic experiences in both general and clinical contexts in Italy. It provides a detailed picture of both qualitative and quantitative aspects of psychotic phenomena, offering valuable insights into the nuanced dimensions of these experiences. This makes it particularly useful for transdiagnostic assessment, examining qualitative differences in psychotic experiences among individuals with different psychiatric disorders, such as schizophrenia and borderline personality disorder, where the phenomenological quality of the experience rather than its quantity is crucial for a deeper understanding.\u003c/p\u003e \u003cp\u003eIn addition to its utility in clinical diagnosis and differentiation, the QPE-I has demonstrated its applicability to non-clinical populations, providing insight into common, often overlooked symptoms. The QPE-I could be very useful for application in psychotherapy settings, allowing clinicians to monitor symptomatology improvements over therapeutic interventions, providing a structured framework for assessing changes in the phenomenology of psychotic symptoms and providing an outcome measure for intervention research.\u003c/p\u003e \u003cp\u003eFurther studies with a larger sample, mixing clinical and non-clinical participants, are needed to confirm and extend the psychometric properties of the QPE-I and to ensure its robustness and applicability across different populations. Nonetheless, the QPE-I stands as a useful tool that significantly enriches the understanding and assessment of psychotic experiences in our country.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eQPE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eQuestionnaire for Psychotic Experiences\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eQPE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eI-Italian version of the Questionnaire for Psychotic Experiences\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAuditory Hallucinations\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eVH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eVisual Hallucinations\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eTotH\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eTotal Hallucinations\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eD\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eDelusions\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePANSS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePositive and Negative Syndrome Scale\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePSYRATS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePsychotic Symptom Rating Scales\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSAPS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eScale for the Assessment of Positive Symptoms\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eNEVHI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eNorth East Visual Hallucinations Interview\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eBDI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eBeck Depression Inventory\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eBAI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eBeck Anxiety Inventory\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eCAPE\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCommunity Assessment of Psychic Experience\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePDI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePeters Delusions Inventory\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSANS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eScale for the Assessment of Negative Symptoms\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSENS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSubjective Experience of Negative Symptoms Scale\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSTAY\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eX-State-Trait Anxiety Inventory\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSCL\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003e90-R-Symptom Checklist-90-Revised\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSOM\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSomatization\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eO\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eC-Obsessive-Compulsivity\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eS-Interpersonal Sensitivity\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eDEP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eDepression\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eANX\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAnxiety\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eHOS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eHostility\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePHOB\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePhobic Anxiety\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePAR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eParanoid Ideation\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePSY\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePsychoticism\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eGSI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eGlobal Severity Index\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePST\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePositive Symptom Total\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePSDI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePositive Symptom Distress Index\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eSP\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSleep Paralysis\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003eEthics approval and consent to participate:\u003c/em\u003e\u003c/strong\u003eThis study was conducted in accordance with the ethical principles outlined in the Declaration of Helsinki. Ethical approval for the study was obtained from the\u003cu\u003e\u0026nbsp;Ethics Committee for Human Experimentation (CESU) of the University of Urbino Carlo Bo\u003c/u\u003e. The committee reviewed and approved the study protocol, ensuring compliance with ethical standards for research involving human participants.\u003c/p\u003e\n\u003cp\u003eAll participants provided informed consent prior to their inclusion in the study. They were fully informed about the purpose, procedures, potential risks, and benefits of the research. Participation was voluntary, and participants were free to withdraw from the study at any time without any consequences. Confidentiality and data protection were maintained in accordance with applicable regulations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eClinical trial number:\u003c/em\u003e\u003c/strong\u003e not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eConsent for publication:\u003c/em\u003e\u003c/strong\u003e does not applies.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAvailability of data and materials:\u003c/em\u003e\u003c/strong\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\u003e\u003cem\u003eCompeting interests:\u003c/em\u003e\u003c/strong\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eFunding:\u003c/em\u003e\u003c/strong\u003eDoes not applies (no funding).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAuthors' contributions:\u003c/em\u003e\u003c/strong\u003e CG conceptualized the study and conducted data collection; MM assisted with data collection and performed data analysis; AQ supported the data analysis; AA supervised the entire project. All authors contributed to drafting the manuscript.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003eAcknowledgements:\u003c/em\u003e\u003c/strong\u003eDoes not applies.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eKraepelin E. Manic Depressive Insanity and Paranoia: J Nerv Ment Dis. 1921 Apr;53(4):350.\u003c/li\u003e\n \u003cli\u003eHinterbuchinger B, Mossaheb N. Psychotic-Like Experiences: A Challenge in Definition and Assessment. Front Psychiatry. 2021 Mar 29;12:582392.\u003c/li\u003e\n \u003cli\u003eArmando M, Nelson B, Yung AR, Saba R, Monducci E, Dario C, et al. Psychotic experience subtypes, poor mental health status and help‐seeking behaviour in a community sample of young adults. Early Interv Psychiatry. 2012 Aug;6(3):300\u0026ndash;8.\u003c/li\u003e\n \u003cli\u003eRossell SL, Schutte MJL, Toh WL, Thomas N, Strauss C, Linszen MMJ, et al. The Questionnaire for Psychotic Experiences: An Examination of the Validity and Reliability. Schizophr Bull. 2019 Feb 1;45(Supplement_1):S78\u0026ndash;87.\u003c/li\u003e\n \u003cli\u003eStaines L, Healy C, Coughlan H, Clarke M, Kelleher I, Cotter D, et al. Psychotic experiences in the general population, a review; definition, risk factors, outcomes and interventions. Psychol Med. 2022 Nov;52(15):3297\u0026ndash;308.\u003c/li\u003e\n \u003cli\u003eBebbington P, Freeman D. Transdiagnostic Extension of Delusions: Schizophrenia and Beyond. Schizophr Bull. 2017 Mar 1;43(2):273\u0026ndash;82.\u003c/li\u003e\n \u003cli\u003eSommer IE, Koops S, Blom JD. Comparison of auditory hallucinations across different disorders and syndromes. Neuropsychiatry. 2012;1\u0026ndash;12.\u003c/li\u003e\n \u003cli\u003eMerrett Z, Rossell SL, Castle DJ. Comparing the experience of voices in borderline personality disorder with the experience of voices in a psychotic disorder: A systematic review. Aust N Z J Psychiatry. 2016 Jul;50(7):640\u0026ndash;8.\u003c/li\u003e\n \u003cli\u003eToh WL, Thomas N, Rossell SL. Auditory verbal hallucinations in bipolar disorder (BD) and major depressive disorder (MDD): A systematic review. J Affect Disord. 2015 Sep;184:18\u0026ndash;28.\u003c/li\u003e\n \u003cli\u003eSommer IE, Koops S, Blom JD. Comparison of auditory hallucinations across different disorders and syndromes. Neuropsychiatry. 2012 Feb;2(1):57\u0026ndash;68.\u003c/li\u003e\n \u003cli\u003eLee K, Chan K, Chang W, Lee EH, Hui CL, Chen EY. A systematic review on definitions and assessments of psychotic‐like experiences. Early Interv Psychiatry. 2016 Feb;10(1):3\u0026ndash;16.\u003c/li\u003e\n \u003cli\u003eHaddock G, McCARRON J, Tarrier N, Faragher EB. Scales to measure dimensions of hallucinations and delusions: the psychotic symptom rating scales (PSYRATS). Psychol Med. 1999 Jul;29(4):879\u0026ndash;89.\u003c/li\u003e\n \u003cli\u003eKay SR, Fiszbein A, Opler LA. The Positive and Negative Syndrome Scale (PANSS) for Schizophrenia. Schizophr Bull. 1987 Jan 1;13(2):261\u0026ndash;76.\u003c/li\u003e\n \u003cli\u003eAndreasen NC. The Scale for the Assessment of Negative Symptoms (SANS): Conceptual and Theoretical Foundations. Br J Psychiatry. 1989 Nov;155(S7):49\u0026ndash;52.\u003c/li\u003e\n \u003cli\u003eMosimann UP, Collerton D, Dudley R, Meyer TD, Graham G, Dean JL, et al. A semi‐structured interview to assess visual hallucinations in older people. Int J Geriatr Psychiatry. 2008 Jul;23(7):712\u0026ndash;8.\u003c/li\u003e\n \u003cli\u003eBeck AT. An Inventory for Measuring Depression. Arch Gen Psychiatry. 1961 Jun 1;4(6):561.\u003c/li\u003e\n \u003cli\u003eBeck AT, Epstein N, Brown G, Steer RA. An inventory for measuring clinical anxiety: Psychometric properties. J Consult Clin Psychol. 1988;56(6):893\u0026ndash;7.\u003c/li\u003e\n \u003cli\u003eYehya A, Khaled SM, Sommer IEC, Elhag SF, Hassan MHMO, Woodruff P, et al. The Arabic Questionnaire for Psychotic Experiences in patients with psychotic disorders: a clinical validation. BMC Psychiatry. 2023 Mar 7;23(1):141.\u003c/li\u003e\n \u003cli\u003eDaneluzzo E, Tommaso SD, Tempesta D, Cerroni G, Stratta P, Rossi A. The Community Assessment Psychic Experience (CAPE): evaluation study of the Italian version. Epidemiol Psichiatr Soc. 2008 Sep;17(3):242\u0026ndash;7.\u003c/li\u003e\n \u003cli\u003eStefanis NC, Hanssen M, Smirnis NK, Avramopoulos DA, Evdokimidis IK, Stefanis CN, et al. Evidence that three dimensions of psychosis have a distribution in the general population. Psychol Med. 2002 Feb;32(2):347\u0026ndash;58.\u003c/li\u003e\n \u003cli\u003ePeters ER, Joseph SA, Garety PA. Measurement of Delusional Ideation in the Normal Population: Introducing the PDI (Peters et al. Delusions Inventory). Schizophr Bull. 1999 Jan 1;25(3):553\u0026ndash;76.\u003c/li\u003e\n \u003cli\u003eSelten JP, Gernaat HBPE, Nolen WA, Wiersma D, Van Den Bosch RJ. Experience of Negative Symptoms: Comparison of Schizophrenic Patients to Patients With a Depressive Disorder and to Normal Subjects. Am J Psychiatry. 1998 Mar 1;155(3):350\u0026ndash;4.\u003c/li\u003e\n \u003cli\u003eLazzari R, Pancheri P. Questionario di Valutazione dell\u0026rsquo;Ansia di Stato e di Tratto (State-Trait Anxiety Inventory). Organizzazioni Speciali, Firenze. 1980;\u003c/li\u003e\n \u003cli\u003eSpielberger CD, Gorsuch RL, Lushene R, Vagg PR, Jacobs GA. Manual for the State-Trait Anxiety Inventory. Consulting Psychologists Press. Palo Alto, CA; 1983.\u003c/li\u003e\n \u003cli\u003ePrunas A, Sarno I, Preti E, Madeddu F, Perugini M. Psychometric properties of the Italian version of the SCL-90-R: A study on a large community sample. Eur Psychiatry. 2012 Nov;27(8):591\u0026ndash;7.\u003c/li\u003e\n \u003cli\u003eTodd DM, Deane FP, McKenna PA. Appropriateness of SCL-90-R adolescent and adult norms for outpatient and nonpatient college students. J Couns Psychol. 1997 Jul;44(3):294\u0026ndash;301.\u003c/li\u003e\n \u003cli\u003eBeaton DE, Bombardier C, Guillemin F, Ferraz MB. Guidelines for the Process of Cross-Cultural Adaptation of Self-Report Measures. Spine. 2000;25(24):3186\u0026ndash;91.\u003c/li\u003e\n \u003cli\u003eLangdon R, McGuire J, Stevenson R, Catts SV. Clinical correlates of olfactory hallucinations in schizophrenia. Br J Clin Psychol. 2011 Jun;50(2):145\u0026ndash;63.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 5 are available in the Supplementary Files section\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-6194339/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6194339/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study presents the preliminary validation of the Italian version of the Questionnaire for Psychotic Experiences (QPE-I), assessing its psychometric properties in a general population sample. The QPE is a comprehensive, transdiagnostic tool designed to assess psychotic phenomena in the areas of auditory, visual, olfactory, tactile hallucinations, and delusions from a qualitative-quantitative perspective in both general and clinical populations. In this study, a total of 87 adult participants completed the QPE-I along with other self-report measures to determine reliability, internal consistency, and validity. The results indicate that the QPE-I largely retains the core structure of the original instrument while being adapted to the Italian context, showing good cross-cultural adaptation, internal consistency, reliability, and convergent and divergent validity. The QPE-I facilitates the transdiagnostic exploration of psychotic experiences, distinguishing qualitative differences in hallucinations and delusions between individuals. It also has potential clinical applications in psychotherapy, providing a means of monitoring symptomatic change and therapeutic outcomes. Further studies with larger and clinical samples are needed.\u003c/p\u003e","manuscriptTitle":"The Questionnaire for Psychotic Experiences: Preliminary validation of the Italian version (QPE-I) in a general population sample","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-03-25 10:31:41","doi":"10.21203/rs.3.rs-6194339/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"093acddd-5c88-4ff8-ab9c-3cb3021542a1","owner":[],"postedDate":"March 25th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-06-05T09:08:25+00:00","versionOfRecord":[],"versionCreatedAt":"2025-03-25 10:31:41","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6194339","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6194339","identity":"rs-6194339","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}