Baseline psychophysiological and cortisol reactivity as a predictor of PTSD treatment outcome in virtual reality exposure therapy

Abstract

Baseline cue-dependent physiological reactivity may serve as an objective measure of posttraumatic stress disorder (PTSD) symptoms. Additionally, prior animal model and psychological studies would suggest that subjects with greatest symptoms at baseline may have the greatest violation of expectancy to danger when undergoing exposure based psychotherapy; thus treatment approaches which enhanced the learning under these conditions would be optimal for those with maximal baseline cue-dependent reactivity. However methods to study this hypothesis objectively are lacking. Virtual reality (VR) methodologies have been successfully employed as an enhanced form of imaginal prolonged exposure therapy for the treatment of PTSD. Our goal was to examine the predictive nature of initial psychophysiological (e.g., startle, skin conductance, heart rate) and stress hormone responses (e.g., cortisol) during presentation of VR-based combat-related stimuli on PTSD treatment outcome. Combat veterans with PTSD underwent 6 weeks of VR exposure therapy combined with either D-cycloserine (DCS), alprazolam (ALP), or placebo (PBO). In the DCS group, startle response to VR scenes prior to initiation of treatment accounted for 76% of the variance in CAPS change scores, p < 0.001, in that higher responses predicted greater changes in symptom severity over time. Additionally, baseline cortisol reactivity was inversely associated with treatment response in the ALP group, p = 0.04. We propose that baseline cue-activated physiological measures will be sensitive to predicting patients’ level of response to exposure therapy, in particular in the presence of enhancement (e.g., DCS).

Targeting memory reconsolidation to prevent the return of fear in patients with fear of flying

“…This is consistent with previous studies identifying discordant findings across subjective fear ratings and psychophysiological arousal (Rothbaum et al., ), suggesting the importance of including a broad and multimodal assessment of fear responses. In the present study, HR and SC were recorded during posttreatment and 3‐month follow‐up assessments as objective markers of fear responses (Norrholm et al., ; Rothbaum et al., ), and results identified significant group‐level differences. The neutral group demonstrated increased SC when viewing the FoF VR clip compared to baseline, suggesting that the neutral group demonstrated increased physiological arousal to the feared exposure compared to the reactivation group at posttreatment and 3‐month follow‐up.…”

“…The psychophysiological data were collected using Biopac for Windows (Biopac Systems, Inc., Aero Camino, CA). We recorded electrodermal activity (EDA) and electrocardiogram (ECG) activity as in previous reports (Norrholm et al., ; Rothbaum et al., ). EDA was assessed using two Ag/AgCl disposable pregelled finger electrodes on the index and middle finger of the nondominant hand.…”

“…One of these studies demonstrates that virtual reality can be effectively used to simulate specific feared situations in a controlled and standardized manner (e.g., Muhlberger et al., ). The present study builds on this research by including the assessment of HR and skin conductance levels (SCLs) while viewing a standardized virtual reality FoF cue during posttreatment and at 3‐month follow‐up assessments as objective markers of arousal and fear responding (Norrholm et al., ; Rothbaum et al., ).…”

Clinical Virtual Reality tools to advance the prevention, assessment, and treatment of PTSD

“…Although there were no differences in treatment outcome across medication conditions, with the exception of posttreatment and three-month follow-up CAPS scores indicating that the alprazolam group showed a higher rate of PTSD than the placebo group, PTSD symptoms significantly improved across all conditions at posttreatment and at the three-, six-, and 12-month follow-ups. Moreover, VRET resulted in improvement in psychobiological measures of startle and cortisol reactivity to a trauma relevant scene (Norrholm et al, 2016), providing further support for the effectiveness of this form of extinction training using VR (Maples-Keller et al, 2017). …”

“…Thus, some researchers have attempted to enhance the objective assessment of PTS by combining VR’s capacity to present users with highly controlled, ecologically relevant, and realistic stimulus environments while concurrently recording psychophysiological/biological responses. The use of VR stimuli for this purpose is at an early stage of maturity, but encouraging results have been reported in four studies that directly address the VR/PTSD assessment question (Costanzo et al, 2014; Highland et al, 2015; Norrholm et al, 2016; Webb et al, 2015). In a somewhat related effort, another paper has examined the use of fMRI to assess changes in brain activation following a course of VRET and PE (Roy et al, 2014).…”