Generalization of fear in post‐traumatic stress disorder

Abstract

Overgeneralization (i.e., the transfer of fear to stimuli not related to an aversive event) is part of alterations in associative fear learning in mental disorders. In the present experimental study, we investigated whether this holds true for post‐traumatic stress disorder (PTSD) related to childhood abuse. We expected that fear generalization under experimental conditions reflects generalization of aversive stimuli to different social domains in real life. Sixty‐four women with PTSD after childhood abuse and 30 healthy participants (HC) underwent a differential fear conditioning and generalization paradigm. Online risk ratings, reaction time, and fear‐potentiated startle served as dependent variables. Based on the subjectively assessed generalization of triggered intrusions across different domains of life, PTSD participants were split into two groups reporting low (low‐GEN) and high (high‐GEN) generalization. PTSD patients reported a higher expectation of an aversive event. During fear conditioning, they assessed the risk of danger related to a safety cue slower and showed a blunted fear‐potentiated startle toward the danger cue. During generalization testing, reaction time increased in the high‐GEN patients and decreased in the HC group with increasing similarity of a stimulus with the conditioned safety cue. Alterations of fear learning in PTSD suggest impaired defensive responses in case of a high threat probability. Moreover, our findings bridge the gap between the generalization of aversive cues during everyday life and laboratory‐based experimental parameters: impairments in the processing of cues signaling safety generalize particularly in those patients who report a spreading of PTSD symptoms across different domains of everyday life.

Relationship between Traumatic Exposure and Posttraumatic Stress Disorder among Flood Victims: Roles of Fear and Self-Disclosure

“…It is necessary to eliminate the atmosphere of fear experienced by people following natural disasters such as floods. These findings suggest that the efficacy of interventions for trauma may be improved by incorporating techniques and principles from emotion-focused therapies to address fear of emotion (Lis et al, 2020).…”

Predicting susceptibility and resilience in an animal model of post-traumatic stress disorder (PTSD)

“…Importantly, susceptible rats explored less the Open Field arena for all the test duration, whereas the NRs and resilient ones moved less at the beginning but started to explore more the arena towards the end of the test displaying an opposite habituation profile with respect to rats not exposed to trauma. This phenotype-specific habituation profile has a high translational value and may be ascribable to fear generalization induced by the traumatic experience, which are key features of PTSD and which consist in the transfer of fear to stimuli not related to the aversive event 34 – 37 .…”

Psychophysiological approaches to understanding the impact of trauma exposure

“…There are a wide range of events and contexts that qualify as potentially traumatizing, and within each of these the “dose” of exposure (i.e., magnitude, frequency) has established associations to functional impairment (see, for instance, Neuner et al, 2004; Elbert et al, 2006; Kaltenbach, Schauer, Hermenau, Elbert, & Schalinski, 2018). As such, we selected studies that cover a wide range of trauma exposure types and trauma‐affected populations, from adolescents growing up in conflict zones ( Shaheen et al, ) or experiencing flight and displacement ( Sill, Popov, Schauer, & Elbert, 2019) to adolescent victims of childhood abuse ( Iffland et al, 2019), adult combat‐exposed veterans ( Grupe, Imhoff‐Smoth, Wielgosz, Nitschke, & Davidson, 2019; Macatee et al, 2019), African civil war survivors ( Conrad et al, 2018; Jovanovic et al, ), adults treated for fear and anxiety disorders including PTSD from various types of trauma ( Harricharan et al, 2019; Jovanovic et al, ; Sambuco, Bradley, Herring, Hillbrandt, & Lang, 2019) and childhood abuse ( Lis et al, 2019). Additionally, using a cross‐generational approach, Serpeloni, Nätt, Goncalvez de Assis, Wieling, and Elbert (2019a) studied epigenetic changes associated with domestic and intrafamilial violence in grandmothers, mothers, and adolescents.…”

“…The selection of articles further reflects the range of measures leveraged in current research on the psychophysiology of trauma exposure. Selected articles demonstrate the utility of fear‐potentiated startle ( Jovanovic et al, 2019; Lis et al, 2019), heart rate ( Grupe et al, 2019; Iffland et al, 2019), and ERPs to decode the translation of trauma exposure into PTSD symptoms ( Macatee et al, 2019; Sill et al, ), together with the power of hemodynamic imaging by means of BOLD responses during emotional scene processing ( Sambuco et al, 2019) or resting‐state connectivity ( Harricharan et al, 2019; Joshi, Duval, Kubat, & Liberzon, 2019).…”

“…When decoding the psychophysiology of trauma exposure, the central nervous system (CNS) measures naturally target emotional learning and memory and threat processing. Whereas Lis et al (2019) concluded a crucial role for compromised expectation with subsequent overgeneralization of threat and undergeneralization of safety signals from fear‐potentiated startle and subjective measures, other articles used structural and functional brain imaging to identify predictors of PTSD susceptibility. Resting‐state network connectivity and activity in response to fear or trauma‐related stimuli in the hippocampus, amygdala, insula, and prefrontal cortex have been found to predict PTSD in trauma‐exposed individuals (e.g., see overviews by Suarez‐Jimenez et al, 2019; Dretsch et al, 2016).…”