Lemborexant for the Treatment of Residual Insomnia in Major Depressive Disorder (MDD)

The goal of this clinical trial is to learn if Lemborexant works to treat residual insomnia in adults with depression that is being treated. It will also learn about how practical, tolerable, and effective Lemborexant is. The main questions it aims to answer are: * Does Lemborexant help participants improve sleep and reduce insomnia symptoms? * How practical is it to use Lemborexant (how many participants join, drop out, and follow the study rules)? How do participants feel about using it (based on surveys and interviews)? Researchers will compare Lemborexant to a placebo (a look-alike substance that contains no drug) to see if Lemborexant works to treat residual insomnia in adequately treated major depressive disorder. Participants will: * Take Lemborexant or a placebo every day for 6 weeks (2 weeks at 5 mg then 4 weeks at 10 mg) * Complete clinical assessments and in-person study visits * Maintain a digital sleep diary and complete daily and weekly self-report ecological momentary assessments (EMAs) * Use a wearable device which will be used to collect and monitor physiological data

NCT Number	NCT06843187
Lead Sponsor	Unity Health Toronto Collaborators: University of Toronto, Centre for Addiction and Mental Health, Toronto Metropolitan University
Conditions	Major Depressive Disorder(MDD), Insomnia Comorbid to Psychiatric Disorder
Enrollment	30 participants
Start Date	2024-09-25
Primary Completion	2026-07-15 (estimated)
Study Completion	2026-07-15 (estimated)
Updated on ClinicalTrials.gov	2026-07-30