Internet-based CBT relapse predictors in remitted major depressive disorder patients

BACKGROUND: Internet-based cognitive behavioral therapy (ICBT) is a promising intervention for major depressive disorder (MDD) at an aggregated level. However, few studies have investigated the relapse rate and factors predicting risk for relapse following successful ICBT. OBJECTIVES: To examine the relapse rate after ICBT for MDD and identify predictors of time-to-relapse. METHODS: A secondary analysis of a randomized controlled trial was conducted. Participants who remitted after the course were included. The relapse rate was calculated by the Kaplan-Meier method. The Cox proportional hazard model was adopted to investigate the potential associated factors. RESULTS: In total, 83 participants were eligible. The relapse rate was 37.1% within 12 months, with the majority occurring after 6 months. Participants with a history of childhood maltreatment (Hazard ratio, HR = 14.001, p = 0.019), experiencing more adverse life events (HR = 1.331, p = 0.003), and not seeking mental healthcare services when needed at follow-up (HR = 5.114, p = 0.049) were more likely to relapse, while for those conscientiously completing the intervention, a lower risk was found (HR = 0.386, p = 0.039). CONCLUSION: Structured relapse prevention strategies are necessary, especially for those with childhood maltreatment experience and undergoing more adverse life events. Emphasis should be put on conscientiously completing therapeutic courses and promptly seeking mental healthcare services when needed.