Group psychosocial interventions for anxiety, depression, and post-traumatic stress disorder in children and adolescents in low- and middle-income countries: A realist systematic review and meta-analysis of randomised controlled trials

Group psychosocial interventions can be a scalable treatment for depression, anxiety, and post-traumatic stress disorder (PTSD) in low- and middle-income countries (LMICs) but effects are heterogeneous. Little is known about how intervention mechanisms and context interact to generate different outcomes in different populations. We conducted a realist systematic review, combining traditional systematic review methods with analysis of intervention mechanisms and contextual factors to further understanding of complex interventions. This involved: (i) a scoping review to build initial theory and inform data extraction and analysis; (ii) systematically searching six databases for randomised controlled trials (RCTs) of group psychosocial interventions for participants aged 0-19 years in LMICs (21 November 2022, updated 26 April 2024); (iii) extracting data on outcomes, contextual factors, and intervention mechanisms to build hypotheses about how context interacts with mechanisms to generate outcomes (context-mechanism-outcome configurations; CMOCs); (iv) narratively synthesising CMOCs into wider programme theories about how and why psychosocial interventions work; (v) meta-analyses and meta-regressions to assess trends and test CMOCs. We included 38 RCTs with data for 6,086 participants (52% female, mean age 13). These data informed 14 programme theories including theories that interventions work best when adapted for participant cognitive level, incorporating age-appropriate activities, accounting for local gender-specific issues, and being culturally adapted. Pooled post-intervention effect sizes were -0.72 (95% CI -1.01 to -0.42, p < 0.001) for depression, -0.90 (95% CI -1.57 to -0.23, p = 0.014) for anxiety, and -0.71 (95% CI -1.05 to -0.38, p < 0.001) for PTSD. The only significant results in meta-regressions were larger effect sizes for older children and in populations without exposure to conflict for depression symptoms only. Socio-demographic and contextual factors may influence how interventions work and help to explain the heterogeneity of effects. More high-quality RCTs with moderation and mediation analyses are needed to explore the transferability of these interventions.PROSPERO registration: CRD42022364043.