Psychosocial interventions for posttraumatic stress disorder in low- and middle-income countries: a Bayesian meta-analysis.

Posttraumatic stress disorder (PTSD) is prevalent and debilitating in low- and middle-income countries (LMICs), yet the effectiveness of psychosocial interventions remains poorly synthesized. This study presents the first comprehensive meta-analysis of their effectiveness for adults with PTSD symptoms in LMICs (PROSPERO CRD42024584333). A literature search was conducted using the PTSD Trials Standardized Data Repository. Additional searches were performed through backward citation tracking and in Embase, Medline, PsycINFO, and PTSDpubs using terms for PTSD, nonpharmacological interventions, and randomized controlled trial (RCT) methodology. Trials published from 1 January 1980 to 23 June 2025 were included. Eligible studies were RCTs evaluating psychosocial interventions in LMICs, with participants exhibiting PTSD symptoms. Effect sizes were aggregated using three-level Bayesian random-effects meta-regressions. Study quality was assessed using Cochrane's RoB 2 tool. Fifty-five RCTs, comprising 5,041 participants, were included. At post-assessment, psychosocial interventions yielded large within-group (g = -1.88; 95% credible interval [CrI], -2.25 to -1.51) and between-group (g = -1.31; 95% CrI, -1.66 to -0.95) effects for PTSD symptoms, both sustained at follow-up. Sensitivity analyses confirmed robustness of results across varying prior specifications. For the secondary outcomes of depression and anxiety, medium to large, sustained effects emerged. Treatments were particularly effective when trauma-focused, delivered face-to-face, and administered to older participants. This meta-analysis supports the use of psychosocial interventions for adults with PTSD symptoms in LMICs. Consistent with guidelines from high-income countries, trauma-focused interventions should be prioritized as first-line treatments. More high-quality research on PTSD treatment in LMICs is urgently needed, particularly in low- and lower-middle-income countries.