Article

Perceived threat predicts the neural sequelae of combat stress

Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, The Netherlands.
Molecular Psychiatry (Impact Factor: 14.5). 01/2011; 16(6):664-71. DOI: 10.1038/mp.2010.132
Source: PubMed

ABSTRACT

Exposure to severe stressors increases the risk for psychiatric disorders in vulnerable individuals, but can lead to positive outcomes for others. However, it remains unknown how severe stress affects neural functioning in humans and what factors mediate individual differences in the neural sequelae of stress. The amygdala is a key brain region involved in threat detection and fear regulation, and previous animal studies have suggested that stress sensitizes amygdala responsivity and reduces its regulation by the prefrontal cortex. In this study, we used a prospective design to investigate the consequences of severe stress in soldiers before and after deployment to a combat zone. We found that combat stress increased amygdala and insula reactivity to biologically salient stimuli across the group of combat-exposed individuals. In contrast, its influence on amygdala coupling with the insula and dorsal anterior cingulate cortex was dependent on perceived threat, rather than actual exposure, suggesting that threat appraisal affects interoceptive awareness and amygdala regulation. Our results demonstrate that combat stress has sustained consequences on neural responsivity, and suggest a key role for the appraisal of threat on an amygdala-centered neural network in the aftermath of severe stress.

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Available from: Guido A van Wingen
    • "This debilitating disorder affects approximately 10% of the population in the United States (Kessler, 2000; Kessler et al., 2005), and carries an economic burden now approximating 85 billion dollars per year (Greenberg et al., 2015). The neurobiology underlying PTSD and related disorders is not well understood (Newport and Nemeroff, 2000), and adding to its complexity is the fact that PTSD can also develop in individuals who simply witness a fearful/traumatic event (Perlman et al., 2011; van Wingen et al., 2011). Unfortunately, there is a considerable gap in our basic understanding of the neurobiological consequences of psychological/emotional stress alone and its influence on mental health of the individual. "
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    • "The design allows for identification of blood-based biomarkers, (epi)genetic analyses and symptom trajectories as this cohort is being followed up at multiple time points up to 10 years post deployment. A small group has been scanned with functional neuroimaging of the brain before and after deployment driving new findings e.g. on the role of the amygdala and glucocorticoid receptor number (Geuze et al., 2012; van Wingen et al., 2011). This special issue contains four studies by Boks et al., van Zuiden et al, Reijnen et al, and Smid et al., published from this cohort. "

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