Clinical Research Directory

Inclusion Criteria: * Male or female participants aged ≥ 18 years at the time of signing the ICF * Insomnia disorder diagnosis according to the Diagnostic and Statistical Manual of Mental Disorders criteria including: Self-reported insufficient sleep quantity defined as subjective Total Sleep Time (TST) ≤ 6.5 hours during the night, associated with difficulties with sleep initiation or maintenance or early-morning awakenings, for at least 3 nights per week during a period of at least 3 months prior to screening visit * Insomnia Severity Index© score ≥ 15 * Presence of insomnia symptoms (TST ≤ 6.5 hours for at least 3 valid nights recording, and average TST ≤ 6.5 hours over 7 nights) confirmed by objective measurements using a home electroencephalogram (EEG) device over a 7-night period during screening * Adequate opportunity for sleep (time in bed ≥ 7 hours for at least 3 valid recorded nights) confirmed by objective measurements obtained using the home EEG device during the 7-night assessment period specified in the inclusion criterion above Exclusion Criteria: * Body mass index \< 18.5 or \> 40.0 kg/m2 * Any lifetime history of breathing-related sleep disorder * Presence of an additional sleep-wake disorder * Self-reported usual daytime napping ≥ 1 hour per day and ≥ 3 days per week * Previous treatment with daridorexant or other dual orexin receptor antagonists at any time prior to Visit 1 * Acute or unstable (i.e., not adequately controlled for at least 1 month) psychiatric condition * Any suicidal ideation or history of suicide attempt, as assessed by Columbia Suicide Severity Rating Scale© (C-SSRS©), at Visit 1 * Unstable medical condition, which, in the opinion of the investigator, could affect the participant's safety or interfere with the trial assessments