Abstract
Social Anxiety Disorder (SAD) has its usual onset during adolescence when it is a highly prevalent and debilitating condition. Evidence regarding the processes that underline social anxiety and SAD is not compelling, especially in adolescents. Within an Acceptance and Commitment Therapy (ACT) framework, the causal role of ACT processes on adolescents' social anxiety and how these processes contribute to sustain social anxiety over time is still unknown. Hence, this study explored the role of psychological inflexibility (PI) and acceptance and committed action (as psychological flexibility processes) on social anxiety over time, in a clinical sample of adolescents. Twenty-one adolescents (Mage = 16.19, SD = 0.750) with a primary diagnosis of SAD completed a set of self-report measures assessing PI, acceptance (i.e., willingness to experience social anxiety symptoms), action (i.e., moving towards valued life directions despite social anxiety symptoms) and social anxiety. Path analysis was used to investigate a mediation model linking acceptance, committed action, and PI to social anxiety, directly and indirectly. Findings revealed that acceptance and action were negatively and directly associated with PI after 10-weeks. In turn, PI yielded a positive and direct effect on social anxiety after another 12-weeks. PI totally mediated the relation between acceptance and action and social anxiety, with significant indirect effects. Overall, findings offer evidence for the applicability of the ACT model to adolescent SAD and support the use of clinical interventions targeting PI to understand and alleviate adolescents' social anxiety.