Effectiveness and cost-effectiveness of a culturally tailored Behavioural Activation intervention (DiaDeM) for treating Depression in Type 2 Diabetes: Protocol for a parallel arm, multi-country, randomised controlled trial in South Asia

Background The co-occurrence of depression among individuals with type 2 diabetes is a recognised global health problem and can lead to poorer health outcomes for both conditions. Behavioural activation is an evidence-based brief, low-cost psychological therapy which can be delivered by trained non-specialists, and is useful in treating depression, particularly in low-resource settings. The aim of this study is to test the effectiveness and cost-effectiveness of culturally adapted behavioural activation for depression in people with both depression and type 2 diabetes in two South Asian countries - Bangladesh and Pakistan. Methods A parallel arm, multi-country randomised controlled trial will be conducted in urban health care facilities providing diabetes services. We will recruit 604 adults in total, and randomise them using a 1:1 allocation ratio to receive culturally adapted behavioural activation (DiaDeM), or optimised usual care. DiaDeM comprises six sessions of behavioural activation with a trained non-mental health facilitator, conducted face-to-face and/or remotely. Optimised usual care includes information on depression, pharmacological and non-pharmacological treatment options for depression and details for accessing help locally. Participants in both arms will be followed up at 6- and 12-months post-randomisation. The primary outcome is the severity of depressive symptoms at 6 months, measured using the 9-item Patient Health Questionnaire (PHQ-9). Secondary outcomes include diabetes control, measured using glycosylated haemoglobin. An embedded process evaluation will evaluate the quality of intervention delivery and explore mechanisms of change and the contextual factors associated with the implementation and observed outcomes of DiaDeM. An economic evaluation will gauge DiaDeM’s cost-effectiveness and estimate the impact of diabetes and depression on economic outcomes. Conclusion There is an urgent need to address the rising burden of depression and chronic physical illnesses, such as type 2 diabetes. Interventions such as DiaDeM, which are culturally relevant and rely on a task-sharing approach, offer a potentially low-cost treatment within existing health services. If found to be effective and cost-effective, DiaDeM may be scaled up to address the mental health ‘treatment gap’ and improve mental and physical health outcomes for people with diabetes in South Asia. Trial registration ISRCTN40885204. Trial registered on 11th April 2023 ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial ISRCTN40885204 ### Funding Statement This study is being carried out under the National Institute of Health Research, Global Health Research project, [Grant reference: Research & Innovation for Global Health Transformation (RIGHT) NIHR200806]. The University of York is the trial sponsor. The views expressed in this publication are those of the author(s) and not necessarily those of the NIHR or the UK Department of Health and Social Care. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. ### 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: Formal ethical approvals have been acquired from the Health Sciences Research Governance Committee (HSRGC), University of York (Ref: HSRGC/2020/409/B), Diabetic Association of Bangladesh (Ref: BADAS-ERC/EC/20/00300), National Bioethics Committee Pakistan (Ref: No.4-87/NBC-578/20/ 1101), Institutional Research and Ethics Forum of Rawalpindi Medical University (Ref:242/IREF/RMU/2020) and Ethics Committee of the Office of Research Innovation & Commercialization (ORIC), Khyber Medical University (KMU),(Ref: DIR/KMU/UEC/25), Pakistan. 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 No datasets were generated or analysed during the current study. All relevant data from this study will be made available upon study completion.