RecruitingPhase 2Drug trialUnderstanding the Role of the Locus Coeruleus in InsomniaThis research project aims to better understand the neurobiological mechanistic underpinnings of insomnia disorder. The main question is whether cortical hyperarousal in individuals with insomnia disorder, measured by electroencephalograhic (EEG) infraslow oscillation coupling of sigma power during non-rapid eye movement (NREM) sleep and theta power during rapid eye movement (REM) sleep, is related to locus coeruleus activity.