Abstract
Few studies have reported long-term follow-up data on selective preventive interventions for adolescents. No follow-up selective preventive transdiagnostic studies for adolescents at-risk for emotional disorders, such as anxiety and depression, have been reported. To fill this gap, this study aims to provide the first follow-up assessment of a randomized controlled trial (RCT) studying selective transdiagnostic prevention in at-risk adolescents. A 12-month follow-up assessment was conducted with subjects who originally received either PROCARE (Preventive transdiagnostic intervention for Adolescents at Risk for Emotional disorders), PROCARE+, which includes the PROCARE protocol along with personalized add-on modules or an active control condition (ACC) based on emotional psychoeducation, and their respective booster session for each experimental condition. 80 subjects (47.5% girls) aged between 12 and 18 years (M = 14.62; SD 1.43) who completed these treatment conditions were available for the 12-month follow-up. The results demonstrate the superior long-term efficacy of the PROCARE+ intervention in mitigating emotional symptoms and obsessive–compulsive symptomatology compared to the PROCARE and ACC conditions, with effect sizes notably exceeding those commonly observed in preventive programs. While the three treatments demonstrated beneficial impacts, the pronounced results associated with PROCARE+ at the 12-month follow-up emphasized the importance of personalized treatment modules and the sustained benefits of booster sessions in the realm of preventive psychological interventions. The findings also highlight the potential role of add-on modules in enhancing the effects of the PROCARE+ condition.