Aim Despite being one of the most disabling symptoms of post‐traumatic stress disorder (PTSD)—disrupting sleep continuity, reinforcing hyperarousal, and worsening psychiatric comorbidity—the physiological signature of Trauma‐related nightmares (TRNs) under naturalistic sleep conditions remains poorly characterized. Methods We used home‐based, multi‐sensor devices from the SOMMEPT cohort to assess whether TRNs display distinct autonomic dynamics before and after awakening. TRN awakenings were self‐marked with the wristband button and validated through electroencephalography (EEG) inspection by a psychiatrist and a sleep physician. Each TRN event ( N = 412) was matched 1:1 to three control conditions: spontaneous awakenings in 60 healthy military participants, awakenings in 34 military PTSD patients without TRNs, and non‐nightmare awakenings from 74 military PTSD patients with TRNs. Pre‐awakening autonomic activity was analyzed over 10 min, and post‐awakening reactivity over a 2‐min window using nonparametric statistics with cluster‐based permutation correction. Results TRNs were associated with heightened sudomotor activity and reduced vagal heart rate variability compared with spontaneous awakenings in healthy controls; differences were weaker versus PTSD patients without TRNs or non‐TRN awakenings. Phasic Electrodermal activity (EDA) showed earlier peaks and prolonged recovery, while movement was lower before TRN‐related awakenings. Post‐awakening, TRNs elicited an abrupt surge: heart rate accelerated within ~40 s and normalized by ~2 min; tonic EDA remained elevated, phasic EDA bursts were longer, slower to recover, and motor activity rose during the first ~80 s. Conclusions TRNs display a distinctive autonomic pattern with pre‐awakening sudomotor buildup and post‐awakening cardiovascular–electrodermal surges, supporting biomarker‐based detection and targeted intervention. Trial registration ClinicalTrials.gov Identifier: NCT04581850.
Feingold et al. (Sat,) studied this question.