Objectives: Identifying those who are most (and least) likely to benefit from a stepped-care approach to cognitive behavioral therapy for insomnia (CBT-I) increases access to insomnia therapies while minimizing resource consumption. The present study investigates non-targeted factors in a single-session of CBT-I that may act as barriers to early response and remission.
Methods: Participants (N = 303) received four sessions of CBT-I and completed measures of subjective insomnia severity, fatigue, sleep-related beliefs, treatment expectations, and sleep diaries. Subjective insomnia severity and sleep diaries were completed between each treatment session. Early response was defined as a 50% reduction in Insomnia Severity Index (ISI) scores and early remission was defined by < 10 on the ISI after the first session.
Results: A single-session of CBT-I significantly reduced subjective insomnia severity scores and diary total wake time. Logistic regression models indicated that lower baseline fatigue was associated with increased odds of early remission (B = -.05, p = .02), and lower subjective insomnia severity (B = -.13, p = .049). Only fatigue was a significant predictor of early treatment response (B = -.06, p = .003).
Conclusions: Fatigue appeared to be an important construct that dictates early changes in perceived insomnia severity. Beliefs about the relationship between sleep and daytime performance may hinder perceived improvements in insomnia symptoms. Incorporating fatigue management strategies and psychoeducation about the relationship between sleep and fatigue may target non-early responders. Future research would benefit from further profiling potential early insomnia responders/remitters.