The Bidirectionality of PTSD and Sleep Disturbances among Firefighters with Military Veteran Status

Introduction: Military veterans represent a large proportion of US firefighters. Both populations experience a relatively high risk for both posttraumatic stress disorder (PTSD) symptomatology and sleep disorders. Firefighters with military veteran status have exhibited greater PTSD symptomatology, depression symptomatology, and sleep disturbances than their civilian firefighter counterparts. Additionally, evidence suggests that the relation between sleep disturbance and PTSD is reciprocal. Purpose: The study’s main purposes are: to investigate (1) the mediating role of sleep disturbance severity in the relationship between military veteran status (MVS) and PTSD symptom severity, and (2) the mediating role of PTSD symptom severity in the relationship between MVS and sleep disturbance severity, controlling for alcohol use and trauma load. It is hypothesized that 1) MVS, PTSD symptom severity, and sleep disturbance severity are positively associated; 2) sleep disturbance severity will mediate the relationship between MVS and PTSD symptom severity and; 3) PTSD symptom severity will mediate the relationship between MVS and sleep disturbance severity. Methods: The data for this archival study was collected as part of a larger study in 2016 that examined stress and health-related behaviors amongst career firefighters in a large, urban fire department. Participants were 748, currently employed, male firefighters/EMS (Mage= 38.66; SD= 8.53) for an urban, career fire department, who also indicated exposure to at least one PTSD Criterion A traumatic event, and fully completed the target measures assessing PTSD symptom severity, sleep disturbance, and theoretically relevant covariates. Results: Pearson bivariate correlations between all variables and possible covariates were collected through correlational analyses. Significant relationships were found between all relevant constructs including PTSD symptom severity and sleep disturbance severity (r = .43, p < vii .001), MVS and PTSD symptom severity (r = .12, p <.01), and MVS and sleep disturbance severity (r = .11, p < .01), supporting the proposed hypothesis. Next, two regression analyses were conducted using Hayes’ (2017) macro PROCESS modeling tool for SPSS to assess the two mediation hypotheses and determine significant indirect effects. Aim one’s hypothesis was supported such that sleep disturbance severity partially mediated the relationship between MVS and PTSD symptom severity (ab=.96, SE =.42, 95% CI [.1570, 1.8114]). Additionally, aim two’s hypothesis was also supported such that PTSD symptom severity fully mediated the relationship between MVS and sleep disturbance severity (ab=.34, SE = .13, 95% CI [.0977, .6050]). Conclusion: A discussion of limitations, clinical implications, and future directions are included.