A Pilot Randomized Controlled Trial (RCT) of Acceptance and Commitment Therapy Versus Cognitive Behavioral Therapy for Chronic Insomnia

Objective To compare the effectiveness of protocols for acceptance and commitment therapy for insomnia (ACT-I) and cognitive behavioral therapy for insomnia (CBT-I) in adults.Method Participants were 37 adults (74.3% women; M = 43.7 years, SD = 10.7) with chronic insomnia who were randomized to 6 weekly group sessions consisting of ACT-I (n = 19) or CBT-I (n = 18). The primary outcome measures were based on the Insomnia Severity Index (ISI) total score, a measure of insomnia complaints, and included the proportions of treatment responders (defined as a change in score of 8 points or more) and remitters (defined as a final score below 8).Results Both treatment modalities significantly reduced insomnia severity. Post-treatment, the proportion of treatment responders was higher in the CBT-I than the ACT-I (64.7% vs. 50.0%, respectively) group and six months later, ACT-I made further improvements whereas CBT-I had a reduced treatment response (58.8% vs. 55.6%, respectively). CBT-I was associated with a higher proportion of insomnia remission at post treatment.Conclusions Both CBT-I and ACT-I are effective, with a higher proportion of insomnia remitters in CBT-I post-treatment. The different change trajectories for the two therapy groups provide insights into behavioral change via a cognitive versus contextual approach.