Description: The experiences and factors that contribute to the production of symptoms of PTSD in individuals who are experience or observe traumatic events are reasonably well understood. What has remained a mystery however, is the general observation that people seem to vary in terms of how susceptible they are to developing PTSD. While it is certainly likely true that factors such as mental health and resilience play a role there is not been any general agreement and how all of this plays out at the level of the brain. The article linked below describes a paper written by researchers with decades of experience studying PTSD in which they draw upon the large research literature into PTSD and offer an intriguing hypothesis about how the issue differential susceptibility might play out at the level of the brain.
Source: What’s really going on in PTSD brains? Experts suggest new theory, ScienceDaily.
Date: October 7, 2016
Photo Credit: US Department of Veterans Affairs
Links: Article Link — https://www.sciencedaily.com/releases/2016/10/161007123407.htm
In the paper described in the linked article above researchers Israel Liberzon and James Abelson look over the now quite large research literature relating to PTSD and issues in brain function and provide an overview of the current theories about how PTSD maps onto the brain. One possibility involves abnormal fear learning looks at how the brain’s fight flight mechanism, controlled within the amygdala, may become over sensitized to the cues traumatic events and thus contributing to the symptoms of PTSD. Second possible theory involves areas of the brain that determine which environmental signals are important and specifically which ones reflects threat and suggests that the hyper-vigilance characteristic of PTSD may be the result of over functioning in this area of the brain. A third possibility is that PTSD involves shortfalls in executive function, characteristically understood to be mapped on the prefrontal cortex areas of the brain, that are important for regulating emotion and in planning and task management. Symptoms of PTSD may arise in executive functions become ineffective in managing emotions in response to certain environmental cues. The researchers looked at all of these theories and suggested that all each made sense within the narrow range of their focus an overarching hypothesis that could potentially encompass all three involves a possible deficit in context processing that would link these three areas of research in relation to PTSD. Specifically if you were to see a bear in the zoo or a model or a stuffed bear wouldn’t likely become fearful or feel threatened. However, if you encountered a bear all taking the garbage out from your semi-rural home you would quite appropriately have a full-blown fear reaction. The context plays a huge role in deciding how best to respond. The researchers suggest that patients with PTSD may feel “unmoored” from the world around them as a consequence experience difficulty in linking their internal emotional responses to the current contexts in which they find themselves. They point out that while this hypothesis remains to be tested that a variety of the more successful therapeutic tools for providing assistance for individuals with PTSD can be seen to possibly be deriving their effectiveness from the ability to help patients become re-grounded to their, now safe, contexts.
Questions for Discussion:
- What are the brain based possible explanations for the symptoms observed in relation to PTSD that the authors of this linked article considered in their effort to come up with a larger overarching theory?
- What do the researchers offer as an alternative brain based explanation for PTSD symptoms and for susceptibility to PTSD?
- How does the new hypothesis involving the role of context processing in PTSD potentially account for the previously identified three theories related to symptoms of PTSD and does this approach suggest some alternatives to how we might choose and guide therapeutic interventions with individuals struggling with PTSD?
References (Read Further):
Israel Liberzon, James L. Abelson. Context Processing and the Neurobiology of Post-Traumatic Stress Disorder. Neuron, 2016; 92 (1): 14 DOI: 10.1016/j.neuron.2016.09.039
Bremner, J. D., & Campanella, C. (2016). Effects of psychotherapy for psychological trauma on PTSD symptoms and the brain. Posttraumatic Stress Disorder: From Neurobiology to Treatment, 413.
MacNamara, A., Rabinak, C. A., Kennedy, A. E., Fitzgerald, D. A., Liberzon, I., Stein, M. B., & Phan, K. L. (2016). Emotion regulatory brain function and SSRI treatment in PTSD: neural correlates and predictors of change. Neuropsychopharmacology, 41(2), 611-618.
Fonzo, G. A., Huemer, J., & Etkin, A. (2016). History of childhood maltreatment augments dorsolateral prefrontal processing of emotional valence in PTSD. Journal of psychiatric research, 74, 45-54.
Grupe, D. W., Wielgosz, J., Davidson, R. J., & Nitschke, J. B. (2016). Neurobiological correlates of distinct post-traumatic stress disorder symptom profiles during threat anticipation in combat veterans. Psychological medicine, 46(09), 1885-1895.