Summary: The goal of this clinical trial is to learn if self-help book can be used to treat obsessive-compulsive disorder (OCD) in adolescents aged 10 to 17. The main questions it aims to answer are: Can adolescents and their parents effectively reduce the severity of the obsessive-compulsive symptoms in adolescents who are already stably taking medications through self-help books? What are the characteris...

Summary: This study is conducted to explore the efficacy and cost-effectiveness of stepped-care internet-based cognitive behavior therapy (sc-ICBT) with reduced support compared to cognitive-behavioral group therapy(CBGT), to identify the optimal transition points for shorter effective stepped treatments, to find clinical indicators that can predict the effectiveness of CBT interventions, and to investigat...