Self-rated sleep quality predicts incident suicide ideation in US military veterans: Results from a 7-year, nationally representative, prospective cohort study

Sleep disturbance is a risk factor for future suicidal behaviours (e.g. suicidal ideation, suicide attempt, death by suicide), and military veterans are at increased risk for both poor sleep and death by suicide relative to civilians. The purpose of this study was to evaluate whether self-reported sleep quality was associated with risk of new-onset suicidal ideation in a 7-year prospective nationally representative cohort study of US military veterans. Multivariable logistic regression analyses were conducted to identify the relation between self-rated sleep quality and incident suicidal ideation in 2,059 veterans without current suicidal ideation or lifetime suicide attempt history at baseline. Relative importance analyses were then conducted to identify the relative variance explained by sleep quality and other significant determinants of incident suicidal ideation. A total of 169 (weighted 8.9%, 95% confidence interval =7.7%-10.3%) veterans developed suicidal ideation over the 7-year study period. Poor self-rated sleep quality was associated with a more than 60% greater likelihood of developing suicidal ideation (relative risk ratio = 1.62, 95% confidence interval = 1.11-2.36), even after adjustment for well-known suicide risk factors such as major depressive disorder. Relative importance analysis revealed that poor self-rated sleep quality accounted for 44.0% of the explained variance in predicting incident suicidal ideation. These results underscore the importance of assessing, monitoring and treating sleep difficulties as part of suicide prevention efforts in military veterans.