An examination of chronotype associations with symptoms of depression, PTSD, and sleep disturbances in US military veterans.

PURPOSE: Chronotype is associated with depression and PTSD, which are common mental health conditions among military veterans. Few studies have examined chronotype in this population, which is known to also have more severe sleep difficulties than non-veteran community-residing adults.

METHODS

In the current study, self-reported sleep and mental health symptoms were examined by chronotype using data collected from US military veterans (N = 144) participating in a multi-site post-deployment health repository. Analysis of covariance was used to assess symptom measure differences by chronotype after adjusting for age and sex.

RESULTS

Consistent with prior research, evening types endorsed greater symptomology across measures of depression and PTSD as compared to morning types. Evening types also endorsed more severe insomnia symptoms and poorer sleep quality, and these relationships were not mediated by sleep duration. Chronotype was not associated with trauma-associated sleep disturbance.

CONCLUSIONS

Consideration of chronotype may be important for case conceptualization in military veterans and those with elevated depression, suicidality, and/or trauma. Assessing chronotype may be important for identifying phenotypes at increased risk of greater psychiatric symptom burden, in addition to understanding treatment response to interventions targeting sleep timing, such as cognitive behavioral therapy for insomnia.

CURRENT KNOWLEDGE/STUDY RATIONALE: Few studies have examined chronotype in military veterans, a population known to have more severe sleep difficulties than non-veteran community-residing adults. In this study, a registry of US military veterans serving since 911 was leveraged to examine chronotype relationship to mental health symptoms.

STUDY IMPACT: Evening types endorsed greater symptomology across self-report measures of insomnia severity, sleep quality, PTSD, and depression. Consideration of chronotype may be important for case conceptualization among military veterans and for identifying phenotypes at increased risk of greater psychiatric burden. Assessment of chronotype may also be important for understanding response to interventions targeting sleep timing, such as cognitive behavioral therapy for insomnia (CBTi).