Circadian factors and coping strategies are central to the expression of PTSD symptoms in post-war soldiers

Background

Accumulating evidence suggests that circadian factors play a significant role in vulnerability to posttraumatic stress disorder (PTSD) [1]. Individual differences in chronotype and sleep quality have been associated with PTSD symptom severity, with sleep disturbances increasingly conceptualized not only as a symptom but also as a potential mechanism in the development and maintenance of the disorder [2]. In parallel, coping strategies—particularly maladaptive coping—have been linked to both sleep disruption and increased PTSD symptoms. However, the interplay between circadian characteristics, coping strategies, and trauma exposure in shaping PTSD outcomes has not been sufficiently examined within a unified framework. The present study was designed to investigate these relationships in a population of soldiers shortly after exposure to war-related stressors

Methods

Participants were recruited through social media and snowball sampling. The final sample included 229 Israel Defense Forces soldiers (regular and reserve, men and women) who served during or following the October 7, 2023 war. Participants completed self-report questionnaires assessing demographic characteristics and military service variables, including warfare exposure (Deployment Risk and Resilience Inventory-2; DRRI-2). Circadian factors were assessed using the Morningness-Eveningness Questionnaire (MEQ) and the Pittsburgh Sleep Quality Index (PSQI). Coping strategies were measured using the Brief COPE and grouped into adaptive and maladaptive coping factors. PTSD symptom severity was assessed using the PTSD Checklist for DSM-5 (PCL-5). Statistical analyses included correlational analyses, group comparisons, multiple linear regression, and mediation models to examine direct and indirect associations among variables. ChatGPT 5.3 was the main tool used to analyze the data and results were verified using Statistica 13.0 (TIBCO Software).

Results

Evening chronotype was associated with poorer sleep quality and higher PTSD symptom severity. Poor sleep quality was strongly associated with increased PTSD symptoms, emerging as one of the most robust correlates in the dataset. Maladaptive coping strategies were also strongly associated with both poorer sleep quality and higher PTSD symptoms. In a multiple regression model, warfare exposure, maladaptive coping, sleep quality, and chronotype independently predicted PTSD symptom severity, with the overall model explaining a substantial proportion of variance (r²=0.63). Mediation analyses indicated that the relationship between chronotype and PTSD symptoms was fully mediated by sleep quality, suggesting that circadian preference exerts its effect primarily through its influence on sleep. Maladaptive coping demonstrated both direct and indirect effects on PTSD symptoms, indicating partial mediation via sleep quality.

Conclusions

The present findings support a model in which sleep quality serves as a central proximal mechanism linking circadian preference, coping-related vulnerability, and trauma exposure to PTSD symptom severity. These results highlight the importance of considering circadian and sleep-related processes alongside psychological factors in understanding PTSD risk. Clinically, the findings suggest that interventions targeting sleep disturbances may have broad therapeutic benefits, potentially reducing PTSD symptoms regardless of whether the underlying vulnerability arises from circadian misalignment, maladaptive coping, or trauma exposure.

References

1. Germain, A. (2013). Sleep disturbances as the hallmark of PTSD: where are we now? Am J Psychiatry, 170, 372-82.
2. Cruz-Sanabria, F., Bruno, S., Bazzani, A., Bonelli, C., Violi, M., Frumento, P. & Faraguna, U. (2023). Associations Between Post-Traumatic Stress Symptoms And Sleep/Circadian Parameters: Exploring The Effect Of Chronotype As A Moderator Variable. Chronobiol Int, 40, 581-595.