Efficacy of group psychotherapy for anxiety disorders: A systematic review and meta-analysis.

Objective: This meta-analysis evaluates the efficacy of group psychotherapy in the treatment of anxiety disorders. Method: A comprehensive literature search using PubMed, PsychInfo, Web of Science, CENTRAL, and manual searches was conducted to locate randomized controlled trials. We found 57 eligible studies (k = 76 comparisons) including 3656 participants receiving group psychotherapy or an alternative treatment for generalized anxiety disorder, social anxiety disorder, and panic disorder. Results: Effect size estimates show that group psychotherapy reduces specific symptoms of anxiety disorders more effectively than no-treatment control groups (g = 0.92, [0.81; 1.03], k = 43) and treatments providing common unspecific treatment factors (g = 0.29 [0.10; 0.48], k = 12). No significant differences were found compared to individual psychotherapy (g = 0.24 [-0.09; 0.57], k = 7) or pharmacotherapy (g = -0.05 [-0.33; 0.23], k = 6). The effects were unrelated to factors of the group treatment. Within head-to-head studies, a significant moderating effect emerged for researcher allegiance. Conclusions: Our results support the efficacy of group psychotherapy for anxiety disorders. They indicate that mixed-diagnoses groups are equally effective as diagnosis-specific groups, although further evidence is required. Future primary studies should address differential effectiveness, include a wider range of therapeutic approaches as well as active comparison groups.