Anhedonia and emotional numbing in treatment-seeking veterans: behavioural and electrophysiological responses to reward

Abstract

Background: Anhedonia is a common symptom following exposure to traumatic stress and a feature of the PTSD diagnosis. In depression research, anhedonia has been linked to deficits in reward functioning, reflected in behavioural and neural responses. Such deficits following exposure to trauma, however, are not well understood.Objective: The current study aims to estimate the associations between anhedonia, PTSD symptom-clusters and behavioural and electrophysiological responses to reward.Methods: Participants (N = 61) were recruited among Danish treatment-seeking veterans at the Department of Military Psychology in the Danish Defence. Before entering treatment, participants were screened with symptom measurement instruments and participated in a joint behavioural-electrophysiological experiment. The experimental paradigm consisted of a signal-detection task aimed at assessing reward-driven learning. Simultaneous electrophysiological-recordings were analysed to evaluate neural responses upon receiving reward, as indicated by the Feedback-Related Negativity (FRN) component.Result: Anhedonia as conceptualized in depression correlated with behavioural learning (r = -0.28, p = .032). Neither anhedonia nor behavioural learning correlated with FRN. However, the anhedonia symptom cluster of PTSD did correlate with FRN (r = 0.29, p = .023). Extending upon this in an exploratory analysis, the specific PTSD-symptom emotional numbing was found to correlate moderately with FRN (r = 0.38, p = .003).Conclusion: The present data suggest that anhedonia in trauma-exposed individuals is related to the anticipatory aspect of reward, whereas the neural consummatory reward response seems unlinked. Interestingly, emotional numbing in the same population is related to the consummatory phase of reward, correlating with the FRN response. This suggests that anhedonia and emotional numbing in response to trauma might pertain to different phases of reward processing.

A systematic review of the psychosocial impact of emotional numbing in US combat veterans

“…Simms, Watson and Doebbelling () proposed a 4‐factor model that combined arousal and numbing symptoms into a new “dysphoria” category, predicated on the premise that numbing overlaps with mood and anxiety disorders. Emerging neuroimaging evidence suggests that EN is indeed a separate construct from dysphoria and anhedonia (Eskelund, Karstoft & Andersen, ; Frewen et al, ). The more recently conceptualized the 5‐factor “Dysphoric Arousal” model includes the same numbing criteria as the earlier King model (Elhai et al, ), but placed sleep, irritability, and concentration problems into a separate fifth cluster.…”

Inhibitory Learning as Prediction Error Feedback Loop

“…In the salience network (SN), CBGTC circuits are postulated to formulate a mechanism for the development and treatment of many psychiatric conditions (Peters, Dunlop, & Downar, 2016). These circuits play a role in disorders such as addiction, schizophrenia, OCD, PTSD, chronic pain, depression, anhedonia, and suicide (Cisler et al, 2018;Gradin et al, 2011;Maia & Frank, 2011;Ploner, Sorg, & Gross, 2017;Schmaal et al, 2019;Shin & Liberzon, 2009;Ubl et al, 2015), which share emotion dysregulation as an etiological and/or maintenance factor (Akram et al, 2020;Der-Avakian & Markou, 2012;Dvir, Ford, Hill, & Frazier, 2014;Eskelund, Karstoft, & Andersen, 2018;Garfield, Lubman, & Yücel, 2014;Riquino, Priddy, Howard, & Garland, 2018;Winer et al, 2017). Thus, abnormalities in CBGTC circuits and prediction errors are not only associated with mental health problems characterized by a lack of cognitive control over maladaptive thoughts, impulsive behaviors, and inattention to relevant internal and external stimuli (Peters et al, 2016), but these circuits may also be relevant to the treatment of disorders which share emotion dysregulation more generally as an etiological and/or maintenance factor.…”

Emotional numbing: A key construct in the assessment of mental health during COVID-19 pandemic

“…Current assessments of emotional numbing mainly come from two perspectives. The first is from a biological perspective, assessing the physiological arousal to emotional stimulus with different valence (Eskelund et al, 2018; Felmingham et al, 2014). Lower physiological reactivity to emotional stimuli indicated higher emotional numbing.…”