| Suicide is a leading cause of death, but efforts to determine mechanisms through which suicidality develops have demonstrated inconsistency. The current study investigated the underlying mechanism between sleep and suicidality. It was hypothesized that reductions in executive functioning and increases in rumination mediate the relationship. Data was collected from individuals across the United States using Amazon’s Mechanical Turk. Participants were invited back six months after initial participation to assess the effects of changes in sleep, executive function, and rumination on suicidality. Structural equation modeling demonstrated that rumination mediated the relationship between sleep at baseline and the presence of suicide ideation at follow-up after controlling for depression. Executive functioning did not significantly contribute to this relationship. These findings have significant clinical implications but more research is needed to understand the directionality of the relationships observed and the impact of current affective states on the relationship. Key Words: suicide, sleep, rumination, executive function |