Cognitive behavioural therapy for insomnia as an early intervention of mood disorders with comorbid insomnia: A randomized controlled trial

Objective: To evaluate the effectiveness of small-group nurse-administered cognitive behavioural therapy for insomnia (CBTI) as an early intervention of mood disorders with comorbid insomnia. Methods: A total of 200 patients with first-episode depressive or bipolar disorders and comorbid insomnia were randomized in a ratio of 1:1 to receiving 4-session CBTI or not in a routine psychiatric care setting. Primary outcome was Insomnia Severity Index. Secondary outcomes included response and remission status; daytime symptomatology and quality of life; medication burden; sleep-related cognitions and behaviours; and the credibility, satisfaction, adherence and adverse events of CBTI. Assessments were conducted at baseline, 3, 6, and 12-month. Results: Only a significant time-effect but no group-by-time interaction was found in the primary outcome. Several secondary outcomes had significantly greater improvements in CBTI group, including higher depression remission at 12-month (59.7% vs. 37.9%, χ² = 6.57, p =.01), lower anxiolytic use at 3-month (18.1% vs. 33.3%, χ² = 4.72, p =.03) and 12-month (12.5% vs. 25.8%, χ² = 3.26, p =.047), and lesser sleep-related dysfunctional cognitions at 3 and 6-month (mixed-effects model, F = 5.12, p =.001 and.03, respectively). Depression remission rate was 28.6%, 40.3%, and 59.7% at 3, 6, and 12-month, respectively in CBTI group and 28.4%, 31.1%, and 37.9%, respectively in no CBTI group. Conclusion: CBTI may be a useful early intervention to enhance depression remission and reduce medication burden in patients with first-episode depressive disorder and comorbid insomnia.