1 - (SYM 22) Effect of a Stepped-care Internet-based Cognitive Behavioral Therapy for Obsessive-compulsive Disorder in China: A Noninferiority Clinical Trial

Objective:

Cognitive behavioral therapy (CBT) is the first-line psychological treatment for obsessive-compulsive disorder (OCD), yet access to trained therapists in China is limited. To improve accessibility and cost-effectiveness, a stepped-care internet-based CBT (SC-ICBT) model was developed to adjust treatment intensity based on patient response. This study evaluated whether SC-ICBT is noninferior to traditional face-to-face cognitive behavioral group therapy (CBGT) while being more cost-effective.

Methods:

This single-blind, controlled trial was conducted at Shanghai Mental Health Center, including two sub-studies examining different step sequences: low-to-high intensity (Study 1) and high-to-low intensity (Study 2).

In Study 1 (Clinical Trial: NCT05528224, 2022–2023), 46 outpatients aged 18–50 years with OCD were partly randomized into SC-ICBT + medication (n=23) or CBGT + medication (n=23). In SC-ICBT, participants first completed self-guided exposure and response prevention (ERP) via a online platform with minimal therapist support. Non-responders at Week 3 (Y-BOCS reduction < 25%) then received additional standardized individual ICBT until Week 6. CBGT participants received standard face-to-face group CBT twice weekly for six weeks.

In Study 2 (Clinical Trial: NCT06659094, 2023–2025), 95 patients were partly randomized to SC-ICBT (n=44) or CBGT (n=51). Here, in SC-ICBT group, participants began with therapist-guided ICBT for three weeks; responders at Week 3 (Y-BOCS reduction ≥25%) transitioned to self-guided ICBT for the remaining three weeks.

Results:

Both SC-ICBT and CBGT models significantly reduced OCD symptoms.Although noninferiority was inconclusive (did not fully meet the 3-point Y-BOCS margin), there were no significant between-group differences in response, remission, or self-rated anxiety, depression, and OCD symptoms in either study. Completion rates were 78% (Study 1) and 82% (Study 2). Both interventions were safe and well tolerated; most adverse events were mild anxiety related to ERP.

Economic analyses showed SC-ICBT reduced per-patient costs by ¥1630.03 (95% CI, ¥926.51–¥2333.55) in Study 1, with a more favorable cost-effectiveness ratio (¥386.98 vs ¥508.73 per Y-BOCS point improvement), and similar trends in Study 2.

Conclusion:

Stepped-care ICBT is an effective, safe, and cost-effective alternative to conventional group CBT for adults with OCD in China. This precision-oriented, online technology-assisted model expands treatment access in resource-limited settings.