RESUMO
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.