Acceptance and commitment therapy as a transdiagnostic approach to adolescents with different anxiety disorders: study protocol.

Adolescence increases vulnerability to mental ill-health, particularly anxiety disorders like Social Anxiety Disorder (SAD) and Generalized Anxiety Disorder (GAD). Still, the understanding of Psychological Flexibility/Inflexibility (PF/PI) as a transdiagnostic framework relevant to explaining these difficulties and the efficacy of Acceptance and Commitment Therapy (ACT) in addressing adolescent SAD and GAD remains limited. Hence, this study has two aims: examining the role of PI/PF on adolescents' mental health and assessing ACT's efficacy for adolescent SAD and GAD. We will collect data from 400 community adolescents and employ network analysis to explore connections between PI/PF processes, anxiety, and flourishing. We will also investigate pathways linking PI/PF processes with flourishing and anxiety across samples (clinical SAD, clinical GAD, and mentally healthy groups), expecting to find similar patterns. Furthermore, a Randomized Controlled Trial with three groups (control, SAD experimental and GAD experimental), each comprising 29 participants, and four assessment moments (pre- and post-intervention and 3- and 6-months follow-up) will be conducted. Similar improvements are anticipated in both experimental groups, driven by changes in PI/PF processes. Findings from this work will provide valuable evidence to PI/PF as accurate conceptualizations of human suffering and expand the transdiagnostic application of ACT to adolescents with anxiety disorders.