Alliance in Group Therapy: A Meta-Analysis

Objective: Alliance is considered to be one of the oldest, most well-researched themes in psychotherapy. This article presents a brief history of alliance, its most common definitions and measures used in group treatment, and a meta-analytic review of the alliance-outcome relationship in group therapy. Method: Major databases were searched for articles published between 1969 and 2019. We conducted a random effects meta-analysis of published articles that reported the relation between alliance and treatment outcome within the group format. Results: Results from 29 studies including 3,628 patients indicate that the weighted average correlation between alliance and treatment outcome is significant r =.17 (p < .001), with a small effect size (corresponding to d = 0.34). Heterogeneity of effect sizes was low (Q = 36.47, df = 28, p =.131, I-2 = 23.2). Two variables were found to moderate the alliance-outcome association (treatment orientation and reporting perspective of alliance). Conclusion: With a substantial link between alliance and outcome established, the importance of therapeutic alliance rupture and repair in group therapy is discussed and treatment guidelines are outlined.