Sleep Inertia

Observational study: The goal of this observational study is to learn about the association between slow wave activity before awakening and post-awakening psychomotor vigilance task in time-fixed, 2-hour, simulated night naps in healthy individuals. The main question aims to answer is: Is the quantity of slow wave activity immediately before awakening associated with post-awakening psychomotor vigilance task metrics when awakened after 2-hour nap at night?

The study population comprises three groups of 30 analyzable participants: Patients with sleep inertia and Major Depressive Disorder, patients with Major Depressive Disorder but without sleep inertia, and controls without mood disorders or sleep inertia. Controls will be patients referred to the Sleep Disorders and Acupuncture Unit for polysomnography as part of the screening process for a sleep disorder. Only controls presenting an apnea-hypopnea index \< 15/h, a periodic leg movements index during sleep \< 15/h and a total sleep time ≥ 6 hours on the video-polysomnography will be analyzed.