Polysomnographic markers of suicidal ideation in untreated unipolar major depressed individuals

Given the major role played by sleep in the particular relationship between suicidality and major depression, the aim of this study was to empirically identify polysomnographic markers specific to suicidal ideation in major depressed individuals in order to allow better suicide prevention in this high-risk subpopulation. Demographic and polysomnographic data from 190 individuals (34 healthy controls and 156 untreated unipolar major depressed individuals) recruited from the sleep laboratory database were analysed. Suicidal ideation were considered present if the score in item G of the Beck Depression Inventory was ≥1 and/or if they were highlighted during the systematic psychiatric assessment conducted on admission to the sleep laboratory. Independently of depression severity, major depressed individuals with suicidal ideation present a decrease in deep NREM sleep (slow-wave sleep) and an increase in light NREM sleep (stage 1 + stage 2) compared to those without suicidal ideation. There are no significant differences for the other polysomnographic parameters. In our study, we highlighted the existence of potential polysomnographic markers of suicidal ideation in untreated unipolar major depressed individuals, which seems to open up new perspectives for the identification and management of individuals at high-risk of suicide in this particular subpopulation.