0141 Short-Term Stability of Sleep Parameters in Comorbid Nightmares and Chronic Insomnia Disorder

Abstract Introduction Nightmares are highly comorbid with insomnia and have been associated, yet not consistently, distinct polysomnographic (PSG) disturbances, such as reduced total sleep time (TST), efficiency slow wave well increased nocturnal awakenings wake after onset (WASO) or abnormal REM sleep. However, most prior studies relied on a single night of PSG the degree stability parameters overall differences between individuals nightmares disorder (NCI), chronic (CID) otherwise good sleeping controls (GSC), remain unknown. Therefore, aim this study was to determine if there were significant amongst these aforementioned groups in way their changes across while being studied lab. Methods A 142 GSC, 126 CID 24 NCI participants underwent 8-hour recordings for 4 consecutive nights. Outcomes included continuity, architecture, REM-related nights 1 through 4. Intraclass correlation coefficients (ICC) mixed-effect variances repeated-measure analysis variance (ANOVA) used short-term between-subjects time-by-group interaction effects, respectively. Results ICC similar all outcomes (ICCs>0.6) except that group did display WASO, stage sleep, latency interval. There no effects (ps>0.05). between-group SOL, number awakenings, TST, latency, episodes (all ps< 0.05), where showed significantly longer SOL (58.10±11.08), shorter TST (6.64 hours±1.02), less (3.81±0.76). Conclusion This suggests greater night-to-night variability disturbance nighttime continuity NCI. These disturbances may be attributed occurrence nightmares, causing wakefulness out level hyperarousal evidenced by relative other groups. data also suggest utility objective measures nightmare research clinical practice alike. Support (if any) National Institutes Health (UL1TR000127)