Psychological and psychosocial interventions to support siblings under 18 of children and adolescents with neurodevelopmental disorders: A systematic review and meta-analysis

Background Typically developing siblings (TDS) of children with neurodevelopmental disorders (NDDs) face distinct psychological and social challenges. Although psychological and psychosocial interventions have been used to support TDS, their effectiveness remains uncertain due to inconsistent findings. This study aimed to synthesize the impact of these interventions on TDS to clarify their efficacy. Methods A systematic review and meta-analysis was conducted following PRISMA guidelines. Databases, including APA PsycINFO, CINAHL Complete, ERIC, MEDLINE, Embase, and Web of Science, were searched from their inception through February 2025. The risk of bias for each included study was assessed using the Cochrane Risk of Bias Tool for Randomized Trials 2.0. Effect sizes (Hedges' g) were calculated using a random-effects model. Moderator analyses, including subgroup analysis and meta-regression, identified key characteristics influencing effectiveness of intervention. Results The systematic review included 22 studies, with 11 eligible for meta-analysis. Moderate to large effect sizes were observed for improvements in attitudes and relationships (Hedges' g = 0.76, p  = 0.002), behavioral problems (Hedges' g = 0.75, p  < 0.001), perceived social support (Hedges' g = 0.71, p  = 0.039), and coping ability (Hedges' g = 1.03, p  = 0.027). Peer-involved interventions and center-based settings demonstrated the strongest effects on behavioral problems. Interventions aimed at improving self-esteem were ineffective, and considerable heterogeneity was observed across outcomes. Conclusion Psychological and psychosocial interventions demonstrate effectiveness in addressing the psychological and social needs of TDS of children with NDDs, highlighting the importance of targeted support.