Abstract
OBJECTIVE: To assess the association of insomnia phenotypes, being insomnia with short sleep duration (ISSD) and insomnia with normal sleep duration (INSD), with suicidality in a randomly selected population-based sample. METHODS: Data were analyzed from the Penn State Adult Cohort. Participants (N = 1741, 52.5 years, 57.4% female) were randomly recruited from the general population between January 1990 through March 1999 and mortality data were available through December 2018. Insomnia symptoms were defined as self-reports of moderate-to-severe difficulties initiating or maintaining sleep, early morning awakening and non-restorative sleep, or having chronic insomnia (n = 719). Short sleep duration was defined as <6 hours of in-lab polysomnography-measured sleep duration (n = 879). Suicidality (SAI; n = 102) was ascertained by a lifetime history of suicidal ideation (SI; n = 84), suicide attempts (SA; n = 48) or death by suicide (DBS; n = 10). RESULTS: Compared to normal sleepers who slept ≥6 hours, participants with ISSD and INSD were associated with 1.72-fold and 2.22-fold increased odds of SAI, respectively; these associations were significant for SI, with 2.09-fold and 2.24-fold increased odds, respectively, but not for SA, after adjusting for physical and mental health comorbidities. ISSD and INSD differed in SAI age of onset and hospitalizations after SA. CONCLUSIONS: The results of this cohort study suggest that both INSD and ISSD phenotypes are associated with increased suicidal ideation, while the INSD phenotype has an earlier age of onset and is more likely to experience hospitalizations after attempting suicide. These results highlight the importance of targeting insomnia symptoms to help prevent suicide.