Cardiovascular and psychological responses to voluntary recall of trauma in posttraumatic stress disorder

Abstract

Voluntary recall of trauma is a key element in exposure-based psychotherapies and can trigger spontaneous dissociative responses such as flashbacks, depersonalisation, and derealisation. In order to examine the associations between cardiovascular and psychological responses to voluntary recollection of trauma, individuals with PTSD recalled a traumatic memory. Heart rate and heart rate variability were recorded continuously and the episodes when different forms of dissociation were experienced during the recall were identified. A significant increase in parasympathetic activity was found during trauma recall, with greater parasympathetic dominance being indicative of greater state depersonalisation/derealisation. Whereas overall decreases in heart rate during trauma recall were associated with increased fear and perceived threat, flashbacks were accompanied by short-term increases in heart rate. These findings demonstrate different types of cardiovascular responses associated with different psychological experiences during trauma recall. Future research directions were discussed.

Keywords: Heart rate variability; PTSD; depersonalisation/derealisation; flashbacks; heart rate; memory recall; • Heart rate elevation indicates fear and flashbacks.; • Initial heart rate increase during the recall of trauma, that declines over time.; • Parasympathetic activation indicates state depersonalization/derealization..

Figure 1.

Procedures.

Figure 2.

Means and standard errors of cardiovascular measures across study phases.

Figure 3.

Second-by-second heart rate during flashback, depersonalisation/derealisation, and mixed episodes. Note 1: Seconds −5 to −1 shown here are the five seconds of ordinary recall heart rates just before flashbacks began.Note 2: The total number of flashback, depersonalisation/derealisation, and mixed episodes involved in this figure were 114, 20, and 19, respectively. Due to varying lengths of the episodes, different percents of the overall data points were involved in calculating the mean HR. For flashback: S1–S10: > 98%; S11–S20: > 43%; S21–S30: > 29%; S31–S43: > 20%. For depersonalisation/derealisation: S1–S10: > 50%; S11–S20: > 40%; S21–S34: > 20%. For mixed periods: S1–S10: > 53%; S11–S16: > 20%.