Adherence, Insomnia Severity, and Sleep Beliefs Predict Treatment Response to CBT-I or ACT-I

Cognitive behavioral therapy for insomnia (CBT-I) relative to acceptance and commitment therapy for insomnia (ACT-I) is associated with a higher chance of post-treatment response, but not at 6-month follow-up. Other predictors of response to CBT-I or ACT-I include adherence, insomnia severity, and sleep beliefs. These study findings were published in the Journal of Sleep Research.

Insomnia affects a significant number of people worldwide. CBT-I is an effective treatment choice, but it does not benefit everyone. As a result, ACT-I emerged as a novel treatment option. While both modalities demonstrated excellent results, there is a lack of consensus on the factors that predict treatment response.

In this randomized clinical trial, the investigators compared the ACT-I and CBT-I treatment types. The researchers aimed to understand the association between treatment response and possible predictors of interest, including treatment type, adherence, insomnia severity, anxiety, depression, and sleep beliefs.

The researchers assessed these predictor variables at baseline. At baseline, post-treatment, and 6-month follow-up, the investigators also determined the percentage of treatment responders (defined as a minimum 8-point reduction on the Insomnia Severity Index [ISI]).

During the study, both ACT-I and CBT-I cohorts received six 120-minute group sessions via Zoom. The main outcome of interest was a participant’s total score on the Insomnia Severity Index and if that score was reduced by 8 points or more.

A total of 152 adults between 18 to 59 years of age with chronic insomnia were included in the study, 115 of whom were women. Participants had a mean (SD) age of 40.4 years (10.1). The researchers did not report any significant differences in baseline characteristics between the CBT-I and ACT-I groups.

In a multivariate logistic regression analysis, the investigators found that CBT-I increased the chances of a beneficial response relative to ACT-I at post-treatment (odds ratio [OR], 2.70; 95% CI, 1.14-6.38). This result did not hold true at 6-month follow-up.

The researchers also found that adherence increased the odds of post-treatment response (OR, 3.07; 95%, 1.28-7.34). Further, each additional point in baseline insomnia severity (OR, 1.15; 95%, 1.01-1.30) and dysfunctional sleep belief scores (OR, 1.02; 95%, 1.00-1.05) raises the odds of post-treatment response. Each additional point in baseline insomnia severity also had increased odds in treatment response at 6-month follow-up (OR, 1.14; 95%, 1.01-1.29).

“In conclusion, cognitive behavioural therapy for insomnia increases the chance of treatment response compared with acceptance and commitment therapy for insomnia,” the study authors concluded. “Moreover, higher adherence, insomnia severity and dysfunctional beliefs about sleep predict treatment outcome in both treatments.”

Study limitations included reliance on self-reported data and lack of generalizability due to a small and skewed sample of participants.

Disclosure: “The authors declare that there is no conflict of interest.”

This article originally appeared on Psychiatry Advisor