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 CSF Aβ42 and/or positive plasma biomarker, and neuronal injury (hippocampal and/or temporal atrophy by MRI)) * MMSE from 12 to 26 * Clinical Dementia Rating CDR from 0.5 to 2 * Use of CNS-active medications is permitted provided the dose has been stable for at least 3 months, including: anticholinesterase drugs (rivastigmine, donepezil, galantamine) or memantine, antidepressants SSRI (e.g. fluoxetine, sertraline, paroxetine…), SNRI (e.g. venlafaxine, duloxetine), neuroleptics (e.g. clozapine, olanzapine, aripiprazole...) or drug for pain level 2 (codeine, tramadol). * 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 * Insti…