0878 REM-Sleep Percentage Predicts Higher Rates of Nightmares and Bad Dreams in Trauma-Exposed Individuals

Introduction Trauma-related nightmares are a major re-experiencing symptom of Posttraumatic Stress Disorder (PTSD). Although trauma-related nightmares have been shown to arise in both REM and NREM in persons diagnosed with PTSD, less is known about their occurrence across the full spectrum of post-trauma sequelae. Methods Individuals exposed to a PTSD Criterion-A trauma within the past 2 years (N=56, 35 females) aged 18 to 40 (M=23.18, SD=4.61) completed a diagnostic interview (Structured Clinical Interview for DSM-IV-TR Axis I Disorders-Non-Patient Edition), the Clinician-Administered PSTD Scale (CAPS-5; M=20.36, SD=12.95) and the PSTD Checklist for the DSM-5 (PCL-5; M=27.35, SD=15.46). Twenty-three met DSM-IV-TR criteria for PTSD. All participants completed 12-27 nights of sleep diaries (M=14.81 days, SD=2.45) containing questions that asked whether a dream was recalled, whether it was a nightmare (causing awakening) or a bad dream, and the degree to which it resembled their trauma (exactly, similar, possibly similar, or unrelated). Participants also underwent a night of ambulatory polysomnography (PSG) following an acclimation night. PSG reports were scored by an experienced RPSGT. N1, N2, N3 and REM as percent of total sleep time (TST) were computed. Rates on a per-diary basis for total nightmares plus bad-dreams (“total negative-dream rate”) as well as total nightmares or bad-dreams exactly-like or similar-to the traumatic event (“trauma-dream rate”) were calculated. Results REM% strongly predicted total negative-dream rate (R=0.481, p=0.0006) as well as trauma-dream rate (R=0.385; p=008). Neither rate was predicted by PSG N1%, N3%, REM latency or sleep efficiency (all p’s >0.33). N2% negatively predicted both rates (p=0.011 and 0.098 respectively) but N2% was also strongly negatively related to REM% (p=0.002). Similarly, PSG TST positively predicted trauma-dream rate (p=0.018) but also positively correlated with REM% (p=0.011). Conclusion A strong association of bad dreams/nightmares and trauma-related nightmares with REM sleep exists across the spectrum of symptom severity following trauma. Interventions focused on quantity, quality or specific features of REM may be novel targets for treating trauma-related nightmares. Support (If Any) R01MH109638