Efficacy of CBT-I and Lemborexant Medication for Different Subtypes of Chronic Insomnia

The primary aims of this study is to contrast the effectiveness of CBT-I and pharmacotherapy (lemborexant) compared to placebo on sleep and mental health outcomes in people with insomnia disorder and anxiety/depressive symptoms. In addition, the study will evaluate whether insomnia phenotypes (i.e., +/- 6hrs of sleep) at baseline moderate the effectiveness of the intervention on both sleep and mental health outcomes.

Participants meeting study criteria will be randomized to one of three conditions (1:1:1) involving a 8-week treatment protocol (6 consultations over an 8-week period): 1) CBT-I, 2) an active hypnotic medication (lemborexant, 5-10 mg at bedtime) or 3) a placebo medication. A stratified-based variable block randomization schedule will be used to assign eligible patients to study arms once they have completed baseline measures. Stratification will be based on objective (EEG-defined) sleep duration (\< 6 h vs. \> 6 h) and age (\< 50 years old vs. \> 50 years old). CBT-I will be provided in six therapy sessions provided over an 8-week period by trained graduate therapists in clinical psychology. Lemborexant and placebo medication (compounded and coded by a pharmacy) will be provided by consulting physicians (blinded) in six consultations over an 8-week period. Physicians will have the option of increasing the initial starting dose from 5 mg to 10 mg if needed. Control participants will receive a placebo medication identical in size and color to the active medication. The assessment phase will include baseline, post-treatment, and 6-month follow-up.