LAUSR

Hyperarousal and abnormal autonomic functioning are among the core manifestations of posttraumatic stress disorder (PTSD). In this study, we examined the association of parasympathetic activity during slow wave sleep (SWS) with self-reported hyperarousal measures in recently traumatized individuals. Individuals exposed to a PTSD Criterion-A trauma within the past 2 years (N=76) aged 18-40 (mean 24.06, SD 4.76), of whom 43% met DSM-5 criteria for PTSD, underwent a night of ambulatory polysomnography (PSG) following an acclimation night. ECG recordings during SWS-sleep periods of at least 5 min were analyzed for 2 parasympathetic indices: Root Mean Square of the Successive Differences (RMSSD) and High Frequency (0.14-0.4Hz) power (HF power) using Kubios software. Hyperarousal indices included the hyperarousal items from the PTSD Checklist for DSM-5 (PCL-5) excluding the sleep item #20 (PCLhyp), those from the Clinician-Administered PTSD Scale (CAPS-5) including sleep items (CAPShyp), as well as a published Hyperarousal Scale (HAS) and Hypervigilance Questionnaire (HVQ). In addition, a Composite Hyperarousal Index (CHI) was computed from combined hyperarousal items on the PCL-5 and the CAPS-5 as well as the HAS total score. SWS RMSSD was negatively associated with PCLhyp (R = -.244, p = 0.035), CAPShyp (R = -.250, p = 0.03), CHI (R = -.280, p = 0.014), and HAS (R = -.229, p = 0.049). SWS HF power was negatively associated with CHI (R = -.227, p = 0.049). The hyperarousal (Criterion E) symptoms of PTSD are associated with lowered parasympathetic tone during SWS across the spectrum of posttraumatic severity from resilient individuals to those diagnosed with PTSD. R01MH109638