Who determines the outcome? A three-level meta-analysis on systemic therapy in children and adolescents

Objective: Systemic therapy (ST) is a well-established treatment approach to reduce symptoms, yet its effects across outcome domains, informants, and assessment methods remain underexplored. Method: We conducted a systematic literature review in multiple databases (PsycINFO, Pubmed, Embase, Cochrane CENTRAL), including RCT-studies comparing ST with a psychosocial control treatment for diagnosed children or adolescents. We conducted a three-level meta-analysis. Risk of bias was assessed using an adaptation for psychotherapy. Results: Overall, we included 44 studies, 370 effect sizes, and 4617 families. The overall effect size was small but significant (g =.16, CI [.09,.23], p <.0001). Contrary to expectations, informants and assessment methods were no significant moderators. Effects were comparable across outcome domains including family functioning (g =.12), caregivers’ psychopathology (g =.12) and patient symptoms (g =.19). Outcomes were mostly based on self-report symptom questionnaires, limiting interpretability. Conclusion: Findings support that ST improves family functioning and caregivers’ psychopathology, underscoring the need for more diverse outcomes.