Psychobiology of PTSD
Moy, Gregory, National Association of School Psychologists. Communique
This article contributes to the general understanding of posttraumatic stress disorder (PTSD) by providing readers with an overview of the neuroendocrine structures and functions involved in responses to traumatic stressors and by describing the roles two psychological processes may play in mediating those responses. The authors distinguish PTSD as one of the few psychiatric conditions that necessarily requires an environmental stressor, namely a traumatic event or series of events. While many individuals may experience traumatic events in their lives, the authors pose the question of why only some people develop psychopathology following trauma while others do not. They introduce cognitive appraisal mechanisms and coping processes as potential mediators in the etiology of the disorder.
The hypothalamic-pituitary axis (HPA) is understood to be a key neuroendocrine pathway in the stress response. The hypothalamus is the primary neural structure through which the brain interfaces with the endocrine system. The pituitary may be conceptualized as the master gland, relaying signals from the hypothalamus to other structures in the endocrine system. One of the chief players in the stress response is the adrenal gland, which secretes Cortisol (commonly known as a stress hormone). Therefore, any substantive psychobiological model of PTSD should demonstrate a link between putative psychological constructs and the dysregulationoftheHPA.
Consistent with many cognitive models of PTSD, the proposed involvement of cognitive appraisals relies on the assumption that perceptions of stressful events as threats are central to the development and maintenance of the disorder. There is evidence that subjective appraisals of events are better predictors of PTSD than the objective characteristics of the events themselves. A greater level of perceived loss, harm, or threat is associated with greater symptoms of posttraumatic stress. Furthermore, posttrauma symptoms may emerge after noncatastrophic events such as a divorce, whereas more biologically relevant trauma such as capture and torture does not necessarily predict PTSD. The authors present evidence from previous studies that link the subjective appraisal of a stressor as being either threatening or challenging as one way to mediate the magnitude of the neuroendocrine stress response. …