Accessible Neurobehavioral Anger-Related Markers for Vulnerability to Post-Traumatic Stress Symptoms in a Population of Male Soldiers

Abstract

Identifying vulnerable individuals prone to develop post-traumatic stress symptoms (PTSS) is of paramount importance, especially in populations at high risk for stress exposure such as combat soldiers. While several neural and psychological risk factors are known, no post-traumatic stress disorder (PTSD) biomarker has yet progressed to clinical use. Here we present novel and clinically applicable anger-related neurobehavioral risk markers for military-related PTSS in a large cohort of Israeli soldiers. The psychological, electrophysiological and neural (Simultaneous recording of scalp electroencephalography [EEG] and functional magnetic resonance imaging [fMRI]) reaction to an anger-inducing film were measured prior to advanced military training and PTSS were recorded at 1-year follow-up. Limbic modulation was measured using a novel approach that monitors amygdala modulation using fMRI-inspired EEG, hereafter termed amygdala electrical fingerprint (amyg-EFP). Inter-subject correlation (ISC) analysis on fMRI data indicated that during movie viewing participants’ brain activity was synchronized in limbic regions including the amygdala. Self-reported state-anger and amyg-EFP modulation successfully predicted PTSS levels. State-anger significantly accounted for 20% of the variance in PTSS, and amyg-EFP signal modulation significantly accounted for additional 15% of the variance. Our study was limited by the moderate PTSS levels and lack of systematic baseline symptoms assessment. These results suggest that pre-stress neurobehavioral measures of anger may predict risk for later PTSS, pointing to anger-related vulnerability factors that can be measured efficiently and at a low cost before stress exposure. Possible mechanisms underlying the association between the anger response and risk for PTSS are discussed.

Tracing the Neural Carryover Effects of Interpersonal Anger on Resting-State fMRI in Men and Their Relation to Traumatic Stress Symptoms in a Subsample of Soldiers

“…Indeed, rumination was found as a powerful predictor of persistent stress symptomatology (Michael et al, 2007 ) and in fact also as a mediator between TSS and anger (Orth et al, 2008 ). Though previous findings provided a neural link between anger and TSS (Gilam et al, 2017 ; Lin et al, 2017 ), the results found here provide a first such link between emotional coping in the aftermath of anger and stress related symptomatology. Nevertheless, our findings necessitate additional inquiry since they were limited by the relatively small sample size which consisted of males only, and that soldiers did not experience actual traumatic events and evidenced moderate levels of TSS.…”

Stress management and health promotion intervention program for police forces

“…Anger seems to be promoted by stress, and reduction of one factor leads to a reduction in the other (Jun and Lee, 2017), although job stressors were associated in general with negative emotions such as anger regardless of the level of irritability of the person (Fida et al, 2014). Moreover, evidence shows that anger is a predictor for stress and stress-related psychopathology, mostly PTSD (Lin et al, 2017) because according to cognitive models of PTSD, anger has an effect on the perception of external threats (Ehlers and Clark, 2000) thus creating a vicious circle between anger and stress. Similarly, negative affect has a strong relation with stress (Watson, 1988), aggravating its negative outcomes on health (Hamama et al, 2013; Hyun et al, 2018; Ma et al, 2017).…”

Anger Modulates Influence Hierarchies Within and Between Emotional Reactivity and Regulation Networks

“…The study was carried out in accordance with the recommendations of the Declaration of Helsinki and approved by the ethics committee of the Tel Aviv Sourasky Medical Center with written informed consent from all subjects. Part of the dataset was used in previous publications (see Raz et al, 2016 ; Lin et al, 2017 ).…”

“…All subjects underwent fMRI while passively viewing an excerpt from an Israeli documentary film “Avenge But One of My Two Eyes” (Mograbi, 2005 ), that was previously used in our lab to induce anger (Raz et al, 2016 ; Lin et al, 2017 ). The excerpt introduces a fierce political confrontation between the director and soldiers at a checkpoint in the West Bank.…”

“…To examine network organization and hierarchy related to implicit emotion regulation, in this fMRI study participants passively viewed an anger-provoking movie. Previous studies conducted on this dataset have shown that during the viewing of this movie excerpt stronger functional connectivity between the salience network and the limbic medial amygdala network was associated with more intense ratings of emotional experience (Raz et al, 2016 ), and that activity in participants’ limbic regions was highly synchronized across subjects using inter-subject correlation analysis (Lin et al, 2017 ).…”