Unguided Internet Based Cognitive Behavioral Therapy Reduces Symptoms of Major Depressive DisorderTrial Shows Internet Based Therapy Reduces Major Depressive Symptoms

BACKGROUND: Unguided internet-based cognitive behavioral therapy (ICBT) is a low-cost and scalable treatment for major depressive disorder (MDD), but its long-term effects in Chinese populations remain unclear. OBJECTIVE: This study aimed (1) to explore the short- and long-term effectiveness of unguided ICBT in treating adults with MDD; (2) to investigate the short- and long-term effects on disease-related symptoms, individual and social functioning, and quality of life; and (3) to assess the acceptability and satisfaction with the ICBT. METHODS: An 8-week randomized controlled trial (ChiCTR2100046425) was conducted between August 2021 and June 2023 in Shenzhen, China, with 159 participants in the immediate ICBT group (7-module ICBT course plus usual care) and 158 in the waitlist control (WLC) group (usual care). The WLC group later completed the same ICBT course and follow-up assessments. Outcome measures (depressive and anxiety symptoms, psychological distress, social functioning, self-efficacy, quality of life, and stigma) were assessed before and after treatment and at 3-, 6-, and 12-month follow-ups for ICBT participants. Remission and response, adherence, and satisfaction were evaluated by predefined standards. RESULTS: Among 300 participants analyzed (mean age 28.49, SD 7.0 years; female: n=225, 75%), dropout rates were 22.4% (34/152) in the immediate ICBT group versus 6.3% (10/158) in the WLC group. At posttreatment, the immediate ICBT group showed greater reduction in depressive symptoms versus WLC (mean difference -3.65, SE 0.60; P<.001; d=0.50), with higher remission (80/121, 66.1% vs 58/148, 39.2%; P<.001) and response rates (50/121, 41.3% vs 27/148, 18.2%; P<.001). At 12-month follow-up, the depressive symptoms were improved compared with that at pretreatment (mean difference -3.90, SE 0.32; P<.001; d=0.70), and no significant change was observed in comparison with the outcomes at posttreatment (mean difference -0.81, SE 0.33; P=.33; d=-0.15). ICBT treatment also exhibited similar short- and long-term effects on secondary outcomes, with significant improvement of disease-related symptoms, individual and social functioning, and quality of life. Moreover, the majority of the participants treated with ICBT reported high acceptability of and satisfaction with the ICBT course. CONCLUSIONS: Unguided ICBT effectively reduces depressive symptoms and enhances functioning in Chinese patients with MDD, with sustained benefits over 12 months. Its scalability and low-cost nature make it a promising option for resource-limited settings.