Autonomic activity, posttraumatic and nontraumatic nightmares, and PTSD after trauma exposure

Abstract

Background Nightmares are a hallmark symptom of posttraumatic stress disorder (PTSD). This strong association may reflect a shared pathophysiology in the form of altered autonomic activity and increased reactivity. Using an acoustic startle paradigm, we investigated the interrelationships of psychophysiological measures during wakefulness and PTSD diagnosis, posttraumatic nightmares, and nontraumatic nightmares. Methods A community sample of 122 trauma survivors were presented with a series of brief loud tones, while heart rate (HRR), skin conductance (SCR), and orbicularis oculi electromyogram (EMGR) responses were measured. Prior to the tone presentations, resting heart rate variability (HRV) was assessed. Nightmares were measured using nightmare logs. Three dichotomous groupings of participants were compared: (1) current PTSD diagnosis (n = 59), no PTSD diagnosis (n = 63), (2) those with (n = 26) or without (n = 96) frequent posttraumatic nightmares, and (3) those with (n = 22) or without (n = 100) frequent nontraumatic nightmares. Results PTSD diagnosis was associated with posttraumatic but not with nontraumatic nightmares. Both PTSD and posttraumatic nightmares were associated with a larger mean HRR to loud tones, whereas nontraumatic nightmare frequency was associated with a larger SCR. EMGR and resting HRV were not associated with PTSD diagnosis or nightmares. Conclusions Our findings suggest a shared pathophysiology between PTSD and posttraumatic nightmares in the form of increased HR reactivity to startling tones, which might reflect reduced parasympathetic tone. This shared pathophysiology could explain why PTSD is more strongly related to posttraumatic than nontraumatic nightmares, which could have important clinical implications.

Rapid eye movement sleep parasympathetic activity predicts wake hyperarousal symptoms following a traumatic event

“…Park et al (2017) reported that individuals with PTSD from combat‐related trauma exhibited decreased waking RMSSD and HF‐power compared to healthy controls, and that daytime HRV measures of PNS activity were negatively associated with hyperarousal symptoms. Further, a study by Mäder et al (2021) conducted in a sample encompassing the participants in the present study found that HR acceleration during a loud‐tone task was associated with greater self‐reported PTSD severity. In that sample, HR acceleration significantly differed between PTSD‐diagnosed participants and trauma‐exposed controls (TECs), but HRV did not (Mäder et al, 2021).…”

“…Further, a study by Mäder et al (2021) conducted in a sample encompassing the participants in the present study found that HR acceleration during a loud‐tone task was associated with greater self‐reported PTSD severity. In that sample, HR acceleration significantly differed between PTSD‐diagnosed participants and trauma‐exposed controls (TECs), but HRV did not (Mäder et al, 2021). In contrast, D'Souza et al (2019) did not find an association between daytime HF‐power and PTSD symptom severity.…”

Solving the nightmare mystery: The autonomic nervous system as missing link in the aetiology and treatment of nightmares.

“…It is possible they feel safer sleeping in the lab, and therefore experience fewer nightmares. Mäder et al (2021) conducted a study with 122 trauma survivors to investigate the interrelationships between waking psychophysiological measures and PTSD, posttraumatic nightmares and nontraumatic nightmares. They found that both those with PTSD and posttraumatic nightmares had increased heart rate reactivity after experiencing a series of loud tones, which the authors suggest might reflect reduced parasympathetic tone.…”

Bad dream frequency predicts mental health needs during the SARS-CoV-2 pandemic

“… Pierce et al, 2020 , Spitzer et al, 2006 , Fancourt et al, 2021 , Faul et al, 2009 , The jamovi project 2021 , Kroenke et al, 2001 , Mäder et al, 2021 , Niedzwiedz et al, 2020 …”