Posttraumatic Stress Disorder Severity and Insomnia‐Related Sleep Disturbances : Longitudinal Associations in a Large, Gender‐Balanced Cohort of Combat‐Exposed Veterans

Few studies have investigated the range and severity of insomnia‐related sleep complaints among veterans with posttraumatic stress disorder (PTSD), and the temporal association between insomnia and PTSD severity has yet to be examined. To examine these associations, a large, gender‐balanced cohort of veterans (N = 1,649) of the Iraq and Afghanistan conflicts participated in longitudinal assessments of PTSD and insomnia‐related symptoms over a period of 2.5 years following enrollment (range: 2–4 years). Data were obtained from multiple sources, including interviews, self‐report assessments, and electronic medical record data. Three‐fourths (74.0%) of veterans with PTSD diagnoses at Time 1 (T1) reported insomnia‐related sleep difficulties on at least half the nights during the past 30 days, and one‐third of participants had received a prescription for a sedative‐hypnotic drug in the past year. Veterans without PTSD had fewer sleep problems overall, although the prevalence of sleep problems was high among all study participants. In longitudinal, cross‐lagged panel models, the frequency of sleep problems at T1 independently predicted increases in PTSD severity at Time 2 (T2), B = 0.27, p < .001, after controlling for gender and relevant comorbidities. Conversely, T1 PTSD severity was associated with increasing sleep complaints at T2 but to a lesser degree, B = 0.04, p < .001. Moderately high rates of sedative‐hypnotic use were seen in veterans with PTSD, with more frequent use in women compared to men (40.4% vs. 35.0%). Sleep complaints were highly prevalent overall and highlight the need for increased clinical focus on this area.