Study to uncover morning fog in depression

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * The patient must have given their free and informed consent and signed the consent form * The patient must be a member or beneficiary of a health insurance plan * Ability to understand, write and read French Inclusion criteria for patients with major depression * Diagnosis of depression according to DSM-5 criteria * Suspicion of a sleep disorder requiring polysomnographic screening * Score for IHSS items 3 and 4 * Score ≥ 1 for group with sleep inertia * Score = 0 for the group without sleep inertia Inclusion criteria for controls * No complaints of sleep inertia (score = 0 on IHSS items 3 and 4) * No excessive daytime sleepiness (Epworth Sleepiness Scale score ≤10), * No depressive symptoms (Hospital Anxiety Depression Scale score \< 8 on items 2, 4, 6, 8, 10, 12, 14). Exclusion Criteria: * The patient is participating in an interventional study * The patient is under safeguard of justice or state guardianship * Unweaned from the following medications for at least 5 half-lives prior to inclusion: wake-promoting or psychostimulant drugs (modafinil, methylphenidate, mazindol, amphetamine, pitolisant, solriamfetol, sodium oxybate), neuroleptics, hypnotics, antidepressants, anxiolytics, antiepileptics, budipine, dopamine agonist and antagonist antiemetics (except domperidone), opiates, gabapentin, pregabalin, benzodiazepines, Z-hypnotics (zolpidem and zopiclone), monoamine oxidase inhibitors, catechol-O-methyltransferase or sedative antihistamines. * Patients with central nervous system diseases: Parkinson's disease, mild cognitive impairment and dementia, progressive supranuclear palsy, multisystem atrophy, Huntington's chorea, amyotrophic lateral sclerosis, epilepsy, history of head trauma with loss of consciousness. * Patients with a malignant neoplastic disease requiring therapeutic treatment in the 12months prior to the screening visit * Other medical or psychiatric illnesses (with the exception of depression in he depression group) which, in the investigator's opinion, could interfere with the study. * History of suicide attempt (including failed attempt), or suicidal ideation in the past month * Chronic alcohol consumption or drug abuse in the previous 6 months * Sleep-wake circadian rhythm disorders and presence of sleep insufficiency according to ICSD-3 criteria * Pregnant, parturient or breast-feeding women.