- Have sleep complaints that meet DSM-5 criteria for a diagnosis of insomnia (e.g., difficulty initiating or maintaining sleep, and/or early morning awakenings with inability to return to sleep for at least 3 nights per week for the past 3 months prior to study start, despite adequate opportunity for sleep) based on the investigator's judgment and by the participant's sleep history, as assessed by the sleep items on the Insomnia Diagnostic Interview and Sleep History assessments.