Longitudinal relationships of insomnia, nightmares, and PTSD severity in recent combat veterans

This observational, longitudinal study of veterans with recent combat exposure describes the prevalence, severity and associations of posttraumatic stress disorder (PTSD), insomnia, and nightmares over time.

Eighty recent combat veterans recruited from Veterans Health Administration primary care settings met inclusion criteria including hazardous alcohol use and at least subthreshold PTSD. Insomnia status and nightmare status were assigned based on the Insomnia Severity Index total score and the PTSD Checklist nightmare item, respectively. Participants were re-assessed six months following their baseline assessment. Analyses of variance compared insomnia and nightmare groups on PTSD, depression, and alcohol use severity. Analyses of covariance (controlling for baseline differences) examined whether insomnia and/or nightmares were associated with the clinical course of PTSD. Persistence of conditions was also examined.

At baseline, 74% presented with insomnia and 61% endorsed distressing nightmares. Insomnia was associated with significantly higher PTSD and depression severity at both baseline and six months. The presence of nightmares was associated with significantly higher PTSD severity at both time points and with depression severity at baseline only. Despite decreases in PTSD and depression severity, insomnia severity was relatively unchanged after six months. The prevalence and severity of nightmare complaints diminished modestly over time.

Among this sample of recent combat veterans, insomnia and nightmares were each strongly associated with the severity of both PTSD and depressive symptoms. Over time, insomnia in particular did not appear to resolve spontaneously and was associated with ongoing PTSD. Addressing insomnia early, therefore, may be a strategy to alter the course of PTSD.