Fear Extinction in Traumatized Civilians with Posttraumatic Stress Disorder: Relation to Symptom Severity

“…Similarly, Richards et al (2022) found that a higher FPS across both conditioned stimuli (CS+ and CS− combined) during early extinction was correlated with elevated DSM-IV hyperarousal symptoms [ 20 ]. However, two prior studies found that DSM-IV intrusion, but not hyperarousal symptoms, were associated with the FPS to a CS+ during early extinction [ 16 , 19 ], contrasting with our findings. A post hoc analysis of our data found that the association of early extinction with PTSD hyperarousal symptoms (and no other symptom clusters) was consistent across two measures of PTSD symptoms, suggesting that these divergent findings may stem from sample heterogeneity, rather than measurement differences (see the Supplementary Materials for additional details).…”

“…These data indicate that PTSD subjects have exaggerated fear expression to threat cues during conditioning and that it takes longer for this exaggerated fear response to extinguish. These findings support our primary hypotheses and are consistent with other recent findings in PTSD (Jovanovic et al 2009 b , 2010; Norrholm et al 2011). Interestingly, individuals with PTSD demonstrated startle responses comparable with those of controls during the latest phase of extinction.…”

“…Patients with PTSD did not discriminate US occurrence between the CSs until late acquisition and even then still maintained the expectation that the US would occur during the CS-. This finding is consistent with previous reports of failure to discriminate between the CS+ and CS-, a general inability to acquire safety signals, and increased fear conditioning in patients with PTSD (Blechert et al, 2007; Duits et al, 2015; Grillon and Morgan, 1999; Jovanovic et al, 2010, 2009; Lissek et al, 2005; Norrholm and Jovanovic, 2011; Norrholm et al, 2011; Orr et al, 2000; Peri et al, 2000). Several prior studies have shown that individuals with PTSD have difficultly discriminating between safety and danger cues as evidenced by no difference in fear potentiated startle magnitude to both cues, which may suggest an impaired ability to translate and inhibit fear responses in the presence of a safety cue and/or tend to generalize fear to stimuli that resemble the CS+(Duits et al, 2015; Jovanovic et al, 2012, 2010; Lissek et al, 2005).…”