The Efficacy of Acceptance and Commitment Therapy for Transitional-Age Youth: A Meta-analysis.

This meta-analysis integrated the findings on the efficacy of acceptance and commitment therapy (ACT) for transitional-age youth (TAY; youth aged 15 to 25) on psychopathology (i.e., internalizing, externalizing and other psychological problems), ACT related processes (i.e., psychological flexibility and self-compassion), well-being (i.e., general and social well-being) and coping (i.e., emotional and cognitive coping). Additionally, we used meta-regression analyses to examine whether effect sizes varied based on the type of (sub) outcome, timing of assessment, various intervention characteristics, type of control group and several sample characteristics. We executed a three-level meta-analytic model in R. Based on 65 studies (n = 5283), we found a moderate effect (Hedges's g = 0.72) of ACT compared to the control conditions on psychopathology, ACT related processes, well-being and coping. The quality of the evidence was very low due to a relatively high risk of bias in the selected studies, considerable heterogeneity in effect sizes and a risk of publication bias. Regarding the meta-regression analyses, we found that ACT was more effective than waitlist and TAU conditions, but equally effective compared to CBT, other treatments (e.g., Rational Emotive Behavior Therapy) and other control conditions (e.g., educational intervention). Our results suggest that ACT is an effective intervention for reducing psychopathology and increasing ACT related processes, well-being and coping in TAY with diverse types and severity of psychological problems. We recommend future research to conduct more high quality research, including larges samples, active control conditions, longer follow-up periods and measures of treatment integrity, in more diverse populations of TAY.