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

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.

Inclusion criteria

• 18 years of age or older at the time of enrolment
• Meeting Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria for insomnia disorder (Duke Sleep Interview), with total Insomnia Severity Index (ISI) score > 10, and score ≥ 2 on either the interference or distress item
• Minimal symptoms of anxiety and/or depression with Patient Health Questionnaire (PHQ-9) > 4 and/or Generalized Anxiety Disorder (GAD-7) > 4
• Ability to read and understand French or English
• Ability to use a smartphone, tablet, or computer, and access to home internet connection

Exclusion criteria

• Presence of a lifetime diagnosis of any psychotic or bipolar disorder
• Untreated psychiatric disorder (e.g., major depression) or risk for suicide
• Substance/alcohol use disorder within the past year
• Any life-threatening or progressive medical illness (e.g., cancer, chronic obstructive pulmonary disease) or neurological degenerative disease (e.g., dementia)
• Current use of sleep-promoting medications (prescribed or over-the-counter) or cannabis-derived products for sleep more than two nights per week
• Current use of tricyclic antidepressants, monoamine oxidase inhibitors, or atypical antidepressants
• Reported diagnosis of sleep disorder other than insomnia (e.g., obstructive sleep apnea, restless legs syndrome, rapid eye movement behavior disorder, delayed phase sleep disorder, narcolepsy)
• Total score > 5 on the Stop-Bang Questionnaire and/or clinical symptoms suggestive of sleep apnea (excessive daytime sleepiness), or Epworth score > 10, restless legs syndrome or other signs of other sleep disorders
• Atypical sleep schedules (i.e., habitual bedtimes later than 2:00 AM and rising times later than 10:00 AM on more than two days/nights per week as documented from a sleep diary)
• Working night shifts more than five nights per month in the last six months
• Consuming 2 or more alcoholic beverages per day regularly (3 days or more per week)
• Any contra-indications to using the study medication, including lung disease/breathing problems (e.g., chronic obstructive pulmonary disease), use of strong or moderate CYP3A inducers (strong - rifampin, carbamazepine, and St. John's Wort) (moderate - bosentan, efavirenz, etravirine, and modafinil), pregnant and breastfeeding women
• Not using any method of birth control