Abstract
PURPOSE: Chronic Insomnia Disorder (CID) is prevalent, yet access to effective treatments is limited. Integrating mindfulness with Cognitive Behavioral Therapy for Insomnia (CBT-I) in an accessible online format may fill this gap. This study evaluated the efficacy of a therapist-guided, internet-delivered Mindfulness-Based Cognitive Therapy for Insomnia (iMBCT-I), which has been scarcely investigated. PATIENTS AND METHODS: In this open-label, parallel-group randomized trial, 82 participants with CID were assigned to the 8-week of iMBCT-I group (n = 41) or a control group receiving a single online session of sleep hygiene education (SHE, n = 41). The primary outcomes were insomnia severity assessed with Insomnia Severity Index (ISI) and insomnia remission (ISI < 8) rate. Secondary outcomes included sleep quality, sleep diary and actigraphy parameters, depressive and anxious symptoms, and quality of life. The primary and the follow-up time-points were week 8 and week 20, respectively. Statistical analyses followed the intention-to-treat principle. RESULTS: No serious adverse events were reported. At week 8, the ISI score in the iMBCT-I group showed a significant decrease compared to the SHE group [mean difference, 95% confidence intervals (CI) = 4.00 (2.22, 5.78), p < 0.001, Cohen's d, 95% CI = 0.99 (0.53, 1.45)]. More participants achieved insomnia remission in the iMBCT-I group [odds ratio, 95% CI = 6.21 (2.24, 17.23), p < 0.001]. The iMBCT-I was also superior on improving sleep quality, sleep onset latency, wakefulness after sleep onset, sleep efficiency, rapid eye movement duration, depressive symptoms and both physical and mental quality of life (all p < 0.05). Linear mixed-effects model showed the maintenance of these effects at the 20-week follow-up for most outcomes. CONCLUSION: Therapist-guided iMBCT-I is effective in reducing insomnia severity in adults with CID with benefits sustained for 20 weeks. TRIAL REGISTRATION: This study has been registered with the Chinese Clinical Trial Registry https://www.chictr.org.cn/ (Registration Number: ChiCTR2400084300).