The impact of mindfulness-based interventions with and without elements of cognitive behavior therapy on stress reduction and externalizing behavior: A multilevel meta-analysis

Persistent externalizing behavior is a prevalent issue that can escalate into criminal activities and recidivism if left untreated. Given the negative consequences, it is important to improve the effectiveness of interventions that target externalizing behavior. Elevated stress levels are often associated with persistent externalizing behavior, suggesting that stress-reducing approaches may enhance therapeutic outcomes. This meta-analysis therefore examines the effectiveness of mindfulness-based interventions (MBIs) in reducing stress and externalizing behavior in adolescents and adults with persistent externalizing behavior. It also evaluates whether MBIs combined with cognitive behavioral therapy (CBT) yield greater effects than MBIs alone and explores potential differences in effectiveness between adolescents and adults. A total of 22 studies (23 reports), comprising 89 effect sizes and 1,474 participants (796 experimental, 678 control), were included. Three-level meta-analytic techniques were used to account for heterogeneity within and between studies. Moderator analyses were conducted for intervention type, sample, publication, and study design characteristics. A significant overall effect was found for MBIs in reducing stress and externalizing behavior. Interventions combining MBIs with CBT were more effective than MBIs alone. Contrary to expectations, no significant differences were observed between adolescents and adults in the effectiveness of MBIs. The results of this multilevel meta-analysis highlight the effectiveness of MBIs in treating persistent externalizing problem behavior in both adolescents and adults. The findings underscore the increased efficacy of MBIs when integrated with CBT, emphasizing their potential in addressing (persistent) externalizing behavior. (PsycInfo Database Record (c) 2026 APA, all rights reserved)