A Meta-Analysis on the Effectiveness of Existential Theory-Based Group Counseling Focusing on Viktor Frankl's Logotherapy

This meta-analysis investigated the effectiveness of existential theory-based group counseling programs, particularly those grounded in Viktor Frankl’s logotherapy. A total of 39 Korean studies (including journal articles and graduate theses) yielded 109 effect sizes. Using R version 4.5.0, the overall mean effect size was calculated as 1.15, indicating a large effect. Notably, session duration emerged as a significant moderator: programs lasting over 121 minutes showed the highest effect size (1.91). Participant characteristics also moderated outcomes, with clinical or at-risk groups demonstrating significantly higher effects (1.51) than general populations. These findings offer a comprehensive synthesis of existential group counseling outcomes in Korea and provide foundational insights for program development and implementation.