Daridorexant to Treat Insomnia in Patients With Mild Cognitive Impairment and Mild to Moderate Alzheimer Disease

Inclusion criteria : * Age \[60-85\] years old * Outpatients * Pre-screening: * Complaints of dissatisfaction with sleep quantity or quality, despite adequate opportunity for sleep, at least 3 nights per week and for at least 3 months, and * Total sleep time causes clinically significant distress or impairment in daytime functioning, and * Total sleep time estimated by interview was below 6 hours, on at least 3 nights per week and for at least 1 month before screening * Baseline PSG (at randomization) assessed TST \< 6 hours and WASO \> 1 hour * Diagnosis of MCI and AD patients at an early stage according to the NIA diagnosis criteria (core clinical criteria for MCI, positive biomarker for CSF Aβ42 and neuronal injury (hippocampal and/or temporal atrophy by MRI)) * MMSE from 12 to 26 * Clinical Dementia Rating CDR from 0.5 to 2 * Possible of CNS drugs if stable dose for at least 3 months: anticholinesterase drugs (rivastigmine, donepezil, galantamine) or memantine * For a male subject who is not sterilized and is sexually active with a female partner of childbearing potential, no contraceptive methods are needed Non inclusion criteria : * Patients significantly dependent on caregivers * Institutionalized patients * Analphabetism or subjects unable to read or/and write * Patients unable to perform the neuropsychological tests * Patients unable to complete the study instruments (sleep diary) * Planned longer stay outside the region that prevents compliance with the vi…