Process of change and efficacy of acceptance and commitment therapy (ACT) for anxiety and depression symptoms in adolescents: A meta-analysis of randomized controlled trials

Abstract

Introduction Recent literature suggests that acceptance and commitment therapy (ACT) may be an effective approach for treating symptoms of depression and anxiety symptoms in adolescents. This review meta-analyzes the efficacy of ACT on adolescent depression and anxiety, emphasizing the role of process variables (i.e., psychological flexibility). Methods We systematically searched MedLine, PsycInfo and Scopus for randomized controlled trials (RCT) investigating the effect of ACT on anxiety/depression in adolescents. Studies were combined using the inverse variance method in a random effects model. Additional subgroup and meta-regression analyses were performed, and risk of bias was assessed. The review was pre-registered (PROSPERO registration number: CRD42023483300). Results Our review included 27 RCTs with a total of 2860 participants. ACT did not outperform CBT but was significantly more effective than other active controls (e.g., treatment as usual) for depression symptoms and inactive controls for all outcomes. ACT was more effective than inactive controls for all outcomes. Improvements in psychological flexibility significantly predicted reductions in between-group depression and anxiety. Younger age and a higher percentage of women predicted better outcomes for some outcomes. Limitations It should be noted that this results may be limited by the fact that all included studies were rated as having a high risk of bias. This is mainly due to the self-reported nature of the measures and the lack of crucial methodological information (e.g., process of randomization and allocation, treatment fidelity assessment). Conclusion Our findings support ACT's efficacy for adolescents, particularly in treating depression symptoms. The proposed mechanism of change (psychological flexibility) plays a significant role in the improvements. ACT is comparable in efficacy to CBT, suggesting its potential as an alternative to traditional cognitive-behavioral approaches.