Treating depressive symptomatology in Congolese Refugees in Uganda and Rwanda: Adapting and Evaluating Community-based Sociotherapy Refugees experience elevated rates of mental health difficulties including depression and post-traumatic stress disorder*1,2,3. Refugees face a wide-range of daily stressors (e.g. lack of access to basic resources, lack of safety and security, risk of family violence) that impact on mental health*4. Guidelines exist for delivering psychosocial support in emergency situations*5, but contention remains about which approaches are most effective, and whether these interventions can be delivered at sufficient scale*6. An absence of highly-skilled professionals means that the 'task-sharing' of roles to lay people is required*7. Community-based approaches offer promise for treating common mental disorders, are socially acceptable, and can decrease pressure on primary healthcare*8,9.  Conflict in the Democratic Republic of Congo has led to large numbers of Congolese refugees in Rwanda and Uganda. Community-based Sociotherapy (CBS) has been delivered to over 20,000 people in Rwanda since 2005 to promote community connections and individual wellbeing after the genocide of 1994*10. CBS is delivered by lay-facilitators over fifteen weekly 3-hour group sessions. The WHO described CBS as an approach that uses 'the interactions between individuals and their social environment to facilitate the re-establishment of values, norms, and relationships...and at the same time provide the opportunity for debate, the sharing of experiences and coping mechanisms'*11, Compared with usual care, CBS resulted in significantly increased civic participation and significantly decreased distress in conflict-affected people in Rwanda at 8 months follow-up*12. The UNHCR has noted the potential of CBS for refugees*13, but it has not yet been evaluated in these populations.  The project will use a mix of disciplines to: 1) adapt CBS and assessment measures for use with Congolese refugees in Rwanda and Uganda; 2) investigate the efficacy and cost-effectiveness of adapted CBS (aCBS) for reducing depressive symptoms in Congolese refugees, and determine whether changes in levels of social capital and daily stressors are integral to changes in depressive symptoms; 3) develop implementation guidance for adapting and disseminating aCBS for refugees across diverse settings in conjunction with the UNHCR.  In the first phase, the Design, Implementation, Monitoring and Evaluation (DIME) approach*14 (which utilises key informant interviews and focus groups) will be used to adapt assessment measures and aCBS content. Then a 2-arm cluster randomised controlled trial (with pilot phase) will compare aCBS to an enhanced care as usual (i.e. training for NGO workers in mental health guidelines and reviewing referral pahways). Adult Congolese refugees (apart from those with complex mental health difficulties, active suicidal ideation and/or intellectual disabilities) will be eligible to participate. This will avoid the risk of participants being stigmatised by the use of mental health labels. Analyses will take account of levels of depressive symptoms (PHQ-9*15), and whether they meet criteria for a depression on the Mini-Internal Neuropsychiatric Interview Depression Module (MINI*16) at baseline. A total of 720 participants will be recruited; 360 per study arm. Assessed outcomes will include levels of distress (SRQ-2018*17), functioning (WHOQoL-BREF*18), social capital (SASCAT*19), wellbeing (WHO-5*20), daily stressors (CDES*21), and Trauma Events Inventory*21. Participants will be assessed at baseline, 16- and 32-weeks post-baseline. A TSC/DMC will monitor the trial. The cost-effectiveness of aCBS will be evaluated. A 'process evaluation'*22 based on Normalisation Process Theory (www.normalizationprocess.org) will be undertaken to explore factors that facilitate and impede engagement with aCBS. A project webpage, Twitter account, briefings, knowledge exchange events, conference presentations and academic papers will disseminate project findings and influence decision makers. COVID-19 The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.