The effect of self-help cognitive behavioral therapy for insomnia on depressive symptoms: An updated meta-analysis of randomized controlled trials

Sleep disturbances commonly occur in patients with depression. Insomnia is considered not only a symptom of but also a risk factor for depression. Psychological treatments for insomnia have been demonstrated to be efficacious in alleviating depressive symptoms. This meta-analysis examined the effect of self-help cognitive behavioral therapy for insomnia (CBT-I) in treating depressive symptoms. A systematic review was performed up to April 2019 in 6 major electronic databases. The literature search retrieved 4190 potentially relevant citations; 30 randomized controlled trials (total N = 5945) that compared self-help CBT-I vs. waiting-list (WL), routine care, no treatment, individual cognitive behavioral therapy (CBT), group CBT and placebo were included in the current review. Random effects models showed significant reduction in self-report depressive symptoms (Hedges’ g = 0.35; 95% CI: -0.47, -0.23) and insomnia symptoms (Hedges’ g = 0.79; 95% CI: -0.56, -1.03) in the self-help CBT-I group when compared to the WL/routine care/no treatment/psychoeducation control group. The findings should be interpreted with caution due to potential publication bias. CBT-I appears to be efficacious in treating depressive symptoms. Given the current results and study limitations, large-scale, high-quality trials that specifically target individuals with a clinical diagnosis of depression are warranted in the future.