1111 INSOMNIA AND SUICIDAL IDEATION AMONG MILITARY PERSONNEL: EXPLORING JOINT SYMPTOM TRAJECTORIES OVER A 12-MONTH PERIOD

Abstract

Over the past decade, the rate of suicide has doubled among US military personnel. This concerning increase highlights the need to identify and investigate novel risk factors for suicide. One risk factor for suicide that has gained attention is insomnia, though methodological limitations (e.g., cross-sectional designs) in existing studies hinder nuanced understanding of the relationship between these variables. The current study addressed these limitations by utilizing a longitudinal sample of military personnel and applying advanced statistical modeling to investigate the relationship between insomnia and suicidal ideation. Participants (N = 788) were non-treatment seeking current and former military service members who endorsed recent suicidal ideation or history of suicide attempt. Participants completed five waves of data collection over the course of a year, including the Insomnia Severity Index (ISI), the Columbia Suicide Severity Rating Scale, and the Patient Health Questionnaire - 9 (depression; PHQ). Preliminary results of an autoregressive cross-lagged panel analysis modeling suicidal ideation and insomnia simultaneously across the first three waves of data indicated good overall model fit, X2 = 26.889, p = .003, RMSEA = .047, 90% CI: .026-.068, SRMR = .037. Results of this model indicated that insomnia predicted subsequent increases in suicidal ideation (b = .014, p = .013), but not vice versa (b = -.267, p = .074). Additional, more nuanced latent difference score modeling will also be utilized to investigate whether levels and/or changes in insomnia symptoms drive subsequent changes in suicide ideation, or vice versa, across all waves of data, while controlling for depression. The current study improves upon limitations in the sleep and suicide literature. Our full results will help clarify the nature of the temporal relationship between insomnia symptoms and suicide ideation, and preliminary findings suggest that this relationship may be best characterized as one that is unidirectional. Results will yield a nuanced understanding of the relationship between insomnia and suicidal behavior among military personnel, which has potential clinical implications, including improved risk assessment, and support for use of clinical interventions for insomnia that could simultaneously lower risk for suicide. DoD: W81XWH-13-2-0032 (PI: Stecker)