Longitudinal assessment of the sleep suicide link in Veterans: methods and study protocol.

Although sleep disruption has emerged as a theoretically consistent and empirically supported suicide risk factor, the mechanistic pathways underlying the sleep-suicide link are less understood. This paper describes the methodology of a study intended to examine longitudinal mechanisms driving the link between sleep and suicide in Veterans at elevated suicide risk. Participants will be 140 Veterans hospitalized for suicide attempt or ideation with plan and intent or those identified through the Suicide Prevention Coordinator (SPC) office as being at acute risk. After study enrollment, actigraphy and ecological momentary assessment (EMA) data will be collected for 8 weeks, with follow-up assessments occurring at 2, 4, 6, 8, and 26 weeks. Participants respond to EMA questionnaires, derived from psychometrically validated assessments targeting emotional reactivity, emotion regulation, impulsivity, suicide risk, and sleep timing constructs, five times a day. First and last daily EMA target sleep parameters including sleep quantity, quality, timing, nightmares, and nocturnal awakenings. During follow-up assessments, participants will complete self-report assessments and interviews consistent with EMA constructs and the Iowa Gambling Task. The primary outcome for aim 1 is suicide ideation severity and for the primary outcome for aim 2 is suicide behavior. Findings from this study will improve our understanding of the dynamic interactions among sleep disturbance, emotion reactivity/regulation, and impulsivity to inform conceptual Veteran sleep-suicide mechanistic models. Improved models will be critical to optimizing the precision of suicide prevention efforts that aim to intervene and mitigate risk in Veteran populations, especially during a period of acute risk.