Effects of a transdiagnostic cognitive behaviour therapy-based programme on the natural course of anxiety symptoms in adolescence.

Background: Anxiety disorders frequently have an onset during adolescence, which when left untreated could lead to a chronic course and outcome. This study aimed to examine the way in which a cognitive behaviour therapy-based programme (Super Skills for Life - adolescent version; SSL-A) could change the course of anxiety symptoms through adolescent's behavioural performance and cardiac function.

Method: Sixty-one adolescents at risk of developing an anxiety disorder (45.30% boys; M = 13.76 years, SD = 0.32) were randomly assigned to either an intervention (IG), placebo (PG), or a waitlist group (WG). Adolescents in the IG participated in SSL-A over an 8-week period. Adolescents in the PG participated in an 8-session school-work programme. Adolescents in the WG did not receive any intervention. Anxiety symptoms were assessed every six months, twice before the intervention, as well as at the post-intervention and six months after the intervention. Participants in the IG additionally underwent a stressful task to assess behavioural performance and cardiac adjustment.

Results: Adolescents in the IG significantly reported lower levels of social phobia and generalised anxiety symptoms at the follow-up assessment compared to the adolescents in the PG and the WG. They also showed a significant improvement in vocal quality and lower discomfort during a stressful task at post-intervention, and showed attenuated cardiac recovery indexes, in terms of sample entropy.

Limitations: The study has a small sample size.

Conclusion: SSL-A changed the natural course of anxiety symptoms, as shown by a significant reduction in social phobia and generalised anxiety symptoms, and a significant improvement in behaviour and physiological (cardiac) function during a stressful situation.