A systematic review and meta-analysis of the association between third-wave cognitive constructs and youth anxiety

A greater understanding of the extent to which the maintenance models underlying mindfulness-based cognitive therapy, acceptance and commitment therapy, and metacognitive therapy, originally developed for adults, are empirically supported in anxious youth is needed to inform theory and treatment. We provide an overview of these models. After systematically searching the literature, we estimated the mean effect sizes of the associations between third-wave cognitive constructs (mindfulness, psychological inflexibility, and metacognitions) and anxiety in youth. There is a medium effect size for mindfulness, a large effect size for psychological inflexibility, and a medium to large effect size for metacognitions and anxiety in youth. Overall, there are many more studies testing metacognition than mindfulness and psychological inflexibility, suggesting reliability and generalizability of the results. Recommendations for future studies investigating the validity of third-wave cognitive components in relation to anxiety are discussed in relation to limitations of the available measures of the constructs and study design.