What's sleep got to do with it? Longitudinal associations between insomnia, PTSD, and alcohol use among U.S. Veterans

U.S. veterans are at risk for insomnia, which often co-occurs with symptoms of posttraumatic stress disorder (PTSD) and alcohol use. Much of the research on veterans and these three constructs is cross-sectional and focused on unidirectional pathways. Recent theoretical and empirical evidence suggests a dynamic interplay between insomnia, PTSD, and alcohol use, yet few longitudinal studies exist. A clearer understanding of these pathways is needed to help inform integrated treatments. Using a sample of 1,230 post-9/11 veterans assessed over four time points across 12 months, we used a latent difference score modeling approach to examine proportional and dynamic change between insomnia, PTSD, and alcohol. Results revealed a complex interplay between all three constructs. Higher prior levels of both PTSD and alcohol use were associated with greater subsequent changes in insomnia symptoms (i.e., worse sleep). Moreover, although veterans drank less frequently as their insomnia symptoms worsened over time, greater changes in insomnia symptoms (i.e., worse symptoms) was a mechanism linking PTSD and more frequent drinking. As the research on interventions addressing insomnia, PTSD, and alcohol is limited, there are opportunities for researchers and clinicians to develop programs that effectively target all three in integrated treatments.