Is Cognitive Behavioral Therapy for Insomnia Effective for Improving Sleep Duration in Individuals with Insomnia? A Meta-Analysis of Randomized Controlled Trials

Lay Summary Chronic insomnia is a common sleep disorder and can be treated effectively with cognitive behavioral therapy for insomnia (CBT-I). Previous research has consistently shown that CBT-I can reduce sleep difficulties such as difficulty falling and maintaining sleep. The effects of CBT-I on increasing sleep duration are less consistent across studies. This meta-analysis reviewed 43 randomized controlled trials of CBT-I published between 01/01/2004 and 05/30/2021 and synthesized the findings of the effects of CBT-I on sleep duration, measured subjectively and objectively. We found that CBT-I increased sleep duration measured by sleep diaries and polysomnography by about 30 min at post-treatment. This effect is weaker in people with older ages. Contrarily, CBT-I is found to lead to a decrease in sleep duration for about 30 min when sleep duration is measured by actigraphy. The discrepant findings between different sleep measurements reinforce the notion that different measures of sleep assess different aspects of sleep, and that different sleep measurements may have different responsiveness to the treatment of insomnia. Additionally, most people do not achieve the recommended sleep duration at the end of CBT-I. Future studies are needed to evaluate interventions that can help individuals with insomnia increase and maintain optimal sleep duration. Background Accumulating evidence suggests that sleep duration is a critical determinant of physical and mental health. Half of the individuals with chronic insomnia report less than optimal sleep duration. Cognitive behavioral therapy for insomnia (CBT-I) is an effective treatment for reducing sleep difficulties in individuals with chronic insomnia. However, its effectiveness for increasing sleep duration is less well-established and a synthesis of these findings is lacking. Purpose To provide a synthesis of findings from randomized controlled trials (RCTs) on the effect of CBT-I on subjective and objective total sleep time (TST). Methods A systematic search was performed on articles published from 2004 to 05/30/2021. A total of 43 RCTs were included in the meta-analysis. Publication biases were examined. Meta-regressions were conducted to examine if any sample or treatment characteristics moderated the effect sizes across trials. Results We found a small average effect of CBT-I on diary-assessed TST at post-treatment, equivalent to an approximately 30-min increase. Age significantly moderated the effects of CBT-I on diary-measured and polysomnography-measured TST; older ages were associated with smaller effect sizes. Contrarily, a negative, medium effect size was found for actigraphy-assessed TST, equivalent to an approximately 30-min decrease. Publication biases were found for diary data at follow-up assessments suggesting that positive findings were favored. Conclusions CBT-I resulted in improvements in TST measured by sleep diaries and polysomnography (in adults). These improvements were not corroborated by actigraphy findings. Theoretical and clinical implications were discussed.

Automated summary

Chronic insomnia is a common sleep disorder that can be effectively treated with cognitive behavioral therapy for insomnia (CBT-I). This meta-analysis reviewed 43 randomized controlled trials and found that CBT-I can increase sleep duration by about 30 minutes, although the findings may vary depending on the measurement method.