Characterising the depression pathway in secondary care: a UK-based epidemiological study of patient characteristics, comorbidities, and treatments

BACKGROUND Depression is a disabling disorder with variable outcomes. In severe cases treatment is provided by specialist mental health care services, yet there is a lack of real-world evidence demonstrating how depression is managed within these settings, and consequently, a limited understanding of how to improve care for this population. AIMS We examine the characteristics of patients receiving secondary mental healthcare for depressive disorders within a UK National Health Service (NHS) provider, and the treatments they receive. We investigate when patients receive treatments, and what predicts the use of specific treatments, improvement, and duration with services, with the aim of comparing real-world care to that advised by national guidelines.

A retrospective cohort study was conducted using de-identified electronic patient records of patients with depression referred to Cambridgeshire and Peterborough NHS Foundation Trust (serving a population ∼0·86 million), between January 2013 and June 2021. ANOVA models examined predictor variables of improvement and duration of care, while survival analyses explored treatment initiation rates and predictors of which treatments were used.

9,083 patients met the study’s inclusion criteria. Almost half of those with depression had additional psychiatric diagnoses, reflecting the complexity of cases in secondary care. Treatment within secondary care was associated with improvements in both depressive and overall symptoms. Patients with a greater degree of psychiatric co-morbidity and those with lower socio-economic status indicators presented with greater overall illness severity at baseline, were more likely to be admitted into hospital, spent longer with services, and improved less than the average. Treatment patterns differed across age groups, sex/gender, socio-economic status, and psychiatric comorbidities. Some nationally recommended further-line treatments appeared to be under-used.

Treatment gaps in further-line treatments for depression exist, highlighting key areas for service improvement. Future work should target patients with complex needs and those who are socio-economically deprived. Competing Interest Statement RNC consults for Campden Instruments Ltd in the area of research software (unrelated to the present work), and receives royalties from Cambridge University Press, Cambridge Enterprise, and Routledge (unrelated to the present work), and is an unpaid non-executive director of Cambridge University Health Partners. All other authors have no conflicts of interest to declare. Funding Statement RNC's research is supported by the UK Medical Research Council (MR/W014386/1, MR/Z504816/1) via DATAMIND, the Health Data Research UK (HDR UK) mental health data hub. For the purpose of open access, the authors have applied a Creative Commons Attribution (CC BY) licence to any Author Accepted Manuscript version arising from this submission. This research was supported in part by the National Institute for Health and Care Research (NIHR) Cambridge Biomedical Research Centre (BRC-1215-20014, NIHR203312) and the NIHR Applied Research Collaboration (ARC) East of England; the views expressed are those of the authors and not necessarily those of the NIHR or the Department of Health and Social Care. LA was supported by the NIHR ARC East of England. Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Cambridgeshire and Peterborough NHS Foundation Trust (CPFT) Research Database holds ethical approvals from the UK NHS National Research Ethics Service (references 12/EE/0407, 17/EE/0442, 22/EE/0264). Individual consent was neither required nor obtained. The current study was approved by the CPFT Research Database Oversight Committee (local reference Z0009). I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes Data availability The analytical code for the study is available from the corresponding author on reasonable request. Raw de-identified data are not publicly available, under the terms of NHS Research Ethics approvals; for details of access and conditions, contact research.database{at}cpft.nhs.uk.