Optimizing indicated cognitive behavioral therapy to prevent child anxiety and depression: A cluster-randomized factorial trial

Identifying effective components can lead to interventions that are less resource-intensive and better suited for real-world needs. In this 2 × 2 × 2 cluster-randomized factorial trial (clinicaltrials.gov NCT04263558), we investigated the effects of three components of an indicated, transdiagnostic CBT intervention for children: 1) Intervention Delivery Format (child group format versus a blended format with group sessions and automated web-based sessions), 2) Parental Involvement in the intervention (group-based versus psychoeducational brochure), and 3) a Measurement Feedback System (MFS; on versus off). The intervention was delivered at schools in a group-based format. The participants (N = 701 children) were school children (age 8–12 years) with elevated symptoms of anxiety or depression, and their parents. The main outcomes were self-reported (N = 633) and parent-reported (N = 725) symptoms of child anxiety and depression post-intervention. The secondary outcome was children's user satisfaction with the intervention. We did not find significant main or interaction effects of Delivery Format, Parental Involvement, or MFS on children's symptom levels. There were no significant effects on children's user satisfaction. Results were compatible with retaining the least resource intensive combination (i.e., blended format, parental brochure, no MFS) in an optimized intervention.