Short-Term Stability and Night-to-Night Variability of Sleep Parameters in Nightmares Comorbid with Chronic Insomnia Disorder Across Multiple Nights of Polysomnography.
Sleep February 1, 2024 C. Paquet, K. Lenker, S. Calhoun et al.
Sleep continuity—particularly the ability to fall asleep and maintain sleep—is more unstable in people who have both nightmares and insomnia than in those with chronic insomnia alone or good sleepers. Over four nights in a sleep lab, the comorbid group showed poor stability in wake after sleep onset and stage 1 sleep, took longer to fall asleep, and had a greater first-night effect in stage 1. Both the comorbid and insomnia-alone groups slept less overall but had fewer awakenings and REM periods than good sleepers. The authors suggest that pre-sleep anxiety and nightmare-related distress may drive these differences.