Effectiveness of a stepped-care programme of WHO psychological interventions in a population of migrants: results from the RESPOND randomized controlled trial.

Migrant populations - including labour migrants, undocumented migrants, asylum seekers, refugees, internationally displaced persons, and other populations on the move - are exposed to a variety of stressors that affect their mental health. We designed and tested the effectiveness of a stepped-care programme consisting of two scalable psychological interventions developed by the World Health Organization (WHO) and locally adapted for migrant populations. A parallel-group randomized controlled trial was conducted in Italy. We recruited migrant adults (≥18 years) with psychological distress (score of at least 16 on the Kessler Psychological Distress Scale, K10). The experimental arm received psychological first aid (PFA) and a stepped-care programme consisting of two WHO interventions adapted for this population group: first, Doing What Matters in Times of Stress (DWM) and, for participants who still reported significant levels of psychological distress after DWM, Problem Management Plus (PM+). Each intervention lasted 5-6 weeks and was delivered remotely by lay facilitators. The control arm received PFA and care as usual (CAU). The primary outcome was the change in symptoms of depression and anxiety from baseline to week 21 after randomization, measured by the Patient Health Questionnaire Anxiety and Depression Scale (PHQ-ADS). Between December 14, 2021 and April 18, 2023, 108 migrants were randomized to the stepped-care intervention and 109 to CAU. Analysis of the primary outcome revealed that participants receiving the stepped-care programme showed a greater reduction in anxiety and depression symptoms compared to those receiving CAU (coefficient: -3.460, standard error, SE: 1.050, p=0.001) at week 21. The same difference was observed at week 7 (coefficient: -3.742, SE=1.008, p<0.001) and week 14 (coefficient: -6.381, SE=1.039, p<0.001). The stepped-care programme was also associated with a greater improvement of depression and anxiety symptoms assessed separately at all timepoints, of post-traumatic stress disorder symptoms at weeks 14 and 21, and of self-assessed problems, function and well-being at all timepoints. No serious adverse events occurred. This study provides evidence supporting the stepped-care delivery of DWM and PM+ for migrant population groups with elevated distress. As these interventions are low-intensity, transdiagnostic and task-shifting, they are highly scalable. Existing evidence-based guidelines and implementation packages should be updated accordingly.