Therapeutic Alliance in Psychosocial Interventions for Youth Internalizing Disorders: A Systematic Review and Preliminary Meta-Analysis

Public Health Significance Statement This systematic review and meta-analysis sheds light on heterogeneity in the relationship between therapeutic alliance and intervention outcomes in youth internalizing disorders (anxiety, depression, and obsessive-compulsive disorder). We found preliminary evidence of heterogeneity with regards to problem type, timing of alliance measurement, and geographic location. This knowledge of "for whom" and "under what circumstances" the alliance contributes most strongly to outcomes can guide efforts to tailor and personalize interventions for youth internalizing disorders by leveraging the therapeutic alliance, thus, enhancing outcomes. We report a systematic review and meta-analysis of studies examining the prospective relationship between therapeutic alliance and outcomes for youth ages 6 to 18 receiving intervention for internalizing disorders, with a primary aim to identify potential sources of heterogeneity. Twenty studies met criteria for the review and 18 studies met criteria for the meta-analysis. The overall size of the alliance-outcome relationship was small and positive (r = 0.18, p < .01). The strength of the alliance-outcome relationship varied by problem type, alliance timing, and geographic location. Effect sizes were significantly smaller in studies of youth anxiety and significantly larger when alliance was measured between Sessions 4-6 and in studies conducted in the United States. We discuss study implications and methodological considerations for future studies.