786 Trait Extraversion is Associated with Increased Suicidal Ideation During Total Sleep Deprivation and Insomnia

Abstract

Abstract Introduction It is known that sleep disturbance is associated with increased suicidal thinking, and completed suicides are most common during the late night/early morning hours, but no studies have examined the role of trait-like individual differences in vulnerability to suicidal ideation during sleep deprivation or insomnia. In two separate studies, we examined whether the trait of extraversion is predictive of changes in suicidal thinking following two nights of sleep deprivation and among individuals meeting criteria for insomnia. Methods Study 1: Twenty-five healthy military personnel (20 males), ages 20–35 completed the NEO-PI-R Extraversion scale and the Suicidal Ideation (SUI) scale of the Personality Assessment Inventory (PAI). Participants completed 77 hours of continuous sleep deprivation. After 56 hours of sleep deprivation, participants completed the SUI scale a second time. Study 2: 1,011 adults aged 18–79 (470 males) were divided into two groups based on the clinical threshold (≥15) on the Insomnia Severity Index (ISI) and completed measures of extraversion and depression, including the suicide item of the Patient Health Questionnaire-9 (PHQ9). Results Study 1: After controlling for caffeine group and changes in PAI Depression, Extraversion scores were used to predict changes in SUI scores using stepwise multiple linear regression. Higher Extraversion was significantly associated with increased non-clinical suicidal ideation following sleep loss, β=.463, partial r=.512, p=.013. Study 2: After controlling for depression, extraversion was more strongly correlated with greater suicidal ideation, particularly for those meeting criteria for insomnia, β=.340, partial r=.387, p<.0000001, compared to those below the threshold, β=.185, partial r=.218, p<.0000001. Conclusion Higher trait extraversion was associated with increased vulnerability to suicidal ideation between rested baseline and total sleep deprivation, and was associated with greater suicidal ideation among those meeting criteria for clinically severe insomnia. These findings point to a potential trait-like vulnerability factor that may further our understanding of sleep disruption in the phenomenology of suicide. Support (if any):