(PS5-D82) Efficacy of an Internet-delivered Version of the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders in Adolescents (iUP-A) for the Indicated Prevention of Depression and Anxiety

Many adolescents suffer from anxiety and depressive symptoms, especially since COVID-19. Preventive interventions could help, above all those with a transdiagnostic cognitive behavior therapy (T-CBT) approach which has scarcely been used in prevention in spite of its potential. Using the internet to deliver preventive interventions might improve access to evidence-based treatments, particularly in times of pandemics or similar conditions. To date, no study has applied online T-CBT for the prevention of anxiety and depression in adolescents. In the present study, we used the Spanish internet-delivered version of the Unified Protocol for Transdiagnostic Treatment of Emotional Disorders in Adolescents (iUP-A; Sandín et al., 2019), a T-CBT program with telephone support by a therapist and involvement of one parent in the treatment, to prevent anxiety and depression in adolescents who showed subclinical symptoms of these disorders (indicated prevention). The adolescents were recruited via school counselors‘ referrals who had observed emotional vulnerabilities in the adolescents. After filling out the screening questionnaire and attending a structured clinical interview, 30 adolescents (56.7% females, age range = 12-18 years, M_age = 14.00, SD_age = 1.89) completed the pre-treatment assessment. The adolescents then did the iUP-A and completed the post-treatment and three-month follow-up assessments. Four adolescents dropped out of the study before the post-treatment assessment and two until the follow-up assessment. Intention-to-treat analyses using Friedman tests and Wilcoxon signed rank tests showed a significant decrease over time in self-reported total anxiety and depressive disorder symptoms (RCADS-30_{total score}: χ² = 11.76, p = .003; from pre-treatment to follow-up: Z = -2.27, p = .033, d = 0.43; from post-treatment to follow-up: Z = -2.82, p = .006, d = 0.28), total anxiety disorder symptoms (RCADS-30_{ANX score}: χ² = 8.40, p = .015; from post-treatment to follow-up: Z = -2.47, p = .018, d = 0.25), major depressive disorder symptoms (RCADS-30_{MDD score}: χ² = 7.98, p = .019; from post-treatment to follow-up: Z = -2.17, p = .039, d = 0.27), panic disorder symptoms (RCADS-30_{PD score}: χ² = 11.51 , p = .003; from post-treatment to follow-up: Z = -3.24, p < .001, d = 0.35) and obsessive-compulsive disorder symptoms (RCADS-30_{OCD score}: χ² = 12.80, p = .002; from pre-treatment to follow-up: Z = -2.73, p = .006, d = 0.43; from post-treatment to follow-up: Z = -2.63, p = .009, d = 0.32; all Z values were based on positive ranks). Results indicate the potential efficacy of the iUP-A for the prevention of anxiety and depressive symptoms in adolescents. Future studies should use a larger sample size, longer follow-up periods, and active or passive control conditions.