What Matters in Psychotherapy Outcomes for Children and Adolescents? A Three-level Meta-Analysis on Systemic Therapy

Background: Systemic Therapy (ST) conceives mental health problems in the context of social systems. However, most previous meta-analyses on ST have focused on symptoms without investigating the outcome-specific effects of outcome domain, informants or assessment methods. Method: We conducted a systematic literature review in multiple databases (PsycINFO, Pubmed, Embase, Cochrane CENTRAL), including randomized controlled trials with a psychosocial control treatment from individuals who suffered from a diagnosed mental disorder. We conducted a three-level meta-analysis differentiating the outcomes with regard to outcome domain, informant, and assessment method. Risk of bias was assessed using the adapted tool for psychotherapy research.Results: In total, we included 44 studies, 370 effect sizes, and 4617 participants. The omnibus test indicated a small significant overall effect size of g = .16 (CI [.09;.23], p< .0001, k = 370, s = 44) in favor of ST. The results revealed no differences with regard to outcome domain, informant, and assessment method. The majority of studies focused on patient self-reports, questionnaires and symptoms. ST revealed similar effect sizes with regard to family system functioning (g = .12, k = 107, s = 23), disorder-specific symptoms (g = .19, k = 129, s = 39), general psychopathology of patients (g = .12, k = 85, s = 28), strength-based outcomes (g = .16, k = 24, s = 10), and caregivers’ psychopathology (g = .12, k = 14, s = 10).Conclusion: This meta-analysis indicates a lack of multiple outcome assessments to evaluate the efficacy of ST. These findings suggest a multi-domain, multi-informant and multi-method approach.