Nightmares do result in psychophysiological arousal: A multimeasure ambulatory assessment study

Abstract

Individuals who frequently experience nightmares report compromised sleep quality, poor daytime mood, and functioning. Previous research has aimed at linking these impairments with altered sleep architecture, but results were inconclusive. One plausible explanation is that only a few studies recorded markers of autonomic nervous system activity. For the first time, this study collected such markers under ecologically valid conditions with ambulatory assessment. In 19 individuals with frequent nightmares (≥1 nightmare/week) and 19 healthy control participants (<1 nightmare/month), measures indicating autonomic activation (heart rate, heart rate variability, respiration cycle length, electrodermal fluctuations, EEG arousals, saliva cortisol, REM density) were collected while applying ambulatory polysomnographic assessment during 3 consecutive nights. When nightmare participants reported a nightmare, we analyzed the last 5 min of REM sleep before awakening and compared these data to their non‐nightmares as well as to the dream episodes of control participants. Overall, there were no general differences in autonomic activation of nightmare sufferers compared to control participants. However, when nightmare participants experienced nightmares, autonomic activation was markedly increased compared to their own non‐nightmares and, to some extent, to control participant’s dreams. Significant intraindividual differences were found for all autonomic measures except in participant’s EEG arousals and cortisol levels. Group differences were found in EEG arousals and heart rate. In conclusion, ambulatory polysomnography demonstrates that nightmares are accompanied by increased autonomic activation. Results support the notion of impaired self‐reported sleep quality caused by one’s autonomic response rather than altered sleep pattern.

Nightmare content during the COVID‐19 pandemic: Influence of COVID‐related stress and sleep disruption in the United States

“…Negatively toned dreams are associated with higher stress levels (De Koninck & Brunette, 1991 ), and nightmares are accompanied by increased autonomic activity and sympathetic tone (Paul et al, 2019 ; Perogamvros et al, 2019 ). Although it's unclear which specific mechanisms are involved in the brain that experiences frequent nightmares, as outlined by Nielsen and Levin ( 2007 ), norepinephrine may be involved.…”

What goes around comes around: Nightmares and daily stress are bidirectionally associated in nurses

“…Studies have shown that days with higher stress are associated with increases in negative emotions and rumination, as well as dysregulated cortisol patterns the next day (Sladek et al, 2020). Higher stress is also associated with less nocturnal blood pressure dipping (Holt-Lunstad et al, 2009;Smart Richman et al, 2010) and higher nocturnal heart rate (Paul et al, 2019), which may indicate elevated nighttime arousal and increase risk for nightmares. Future studies should examine possible psychophysiological mediators of links between daily stress and nightmares.…”

Mental Sleep Activity and Disturbing Dreams in the Lifespan

“…A recent study highlighted that the activation of the autonomic nervous system could be associated with nightmares [161]. Paul et al [161] hypothesized that nightmares, as a kind of psychological stressor, would activate two different autonomic responses.…”

“…A recent study highlighted that the activation of the autonomic nervous system could be associated with nightmares [161]. Paul et al [161] hypothesized that nightmares, as a kind of psychological stressor, would activate two different autonomic responses. They found an increase in heart rate frequency, breathing cycle length, electrodermal responses, and REM sleep density, showing increased autonomic activity in people who experienced nightmares [161].…”

“…Paul et al [161] hypothesized that nightmares, as a kind of psychological stressor, would activate two different autonomic responses. They found an increase in heart rate frequency, breathing cycle length, electrodermal responses, and REM sleep density, showing increased autonomic activity in people who experienced nightmares [161]. These results are consistent with the assumption that high emotional charge in dreams results in increased arousal [162].…”