Biopsychology of #Resilience and #StressInoculation

How do you evaluate clients level of resilience and "stress inoculation"? A client may have better-coping mechanisms & an HPA-axis that regulates hormones more efficiently because they've been through tough times. Has your client handled unexpected stressful events throughout the course of their life and come out the other side a little stronger? 

The idea behind the “stress inoculation” effect is based on the hypothesis that exposure to moderate amounts of stress over a prolonged period of time helps an individual develop better-coping mechanisms, better resilience. Potentially.

Scientific researchers Russo, Murrough, Han, Charney & Nestler (2012) have studied the adaptive biopsychology of resilience in terms of an active behavioral, neural, molecular, and a hormonal basis.

These researchers state that the phenomenon of resilience has remained a mystery, biopsychologically speaking. Yet remarkably a high percentage of people exposed to intense levels of trauma and stress manage to maintain a relatively normal psychological homeostasis, (p. 1). “Within the general population, between 50–60% experience a severe trauma, yet the prevalence of illness is estimated to be only 7.8%. Children in particular display remarkable resilience across a range of negative environmental stressors”, (p. 6). Could this be an example of stress inoculation? Interestingly, "..."Stress resilience is enhanced in specific populations, such as military personnel and rescue workers, through controlled exposure to stress–related stimuli". Here is a population whose primary work exposes them. What biological factors allow for this?

To explore the underpinnings of this phenomenon, they examined the role of the neuroendocrine system as the neurobiological coping mechanism. Basically, the neuroendocrine system is the “house” that regulates the hypothalamus and other mechanisms involved in the maintenance of a person’s overall homeostasis. This includes a person’s regulatory systems like metabolism, hunger, energy output and blood pressure levels. Research shows the neurobiology of resilience is mediated by the presence of unique molecular adaptations in the neuroendocrine system: the hypothalamic-pituitary-adrenal (HPA) axis, production of Dehydroepiandrosterone (DHEA) and Testosterone. 

The HPA axis is the main mediator of the initial impact of stress on the brain. It regulates hormonal, neurochemical, and physiological changes. “Glucocorticoids, released from the adrenal cortex as a consequence of HPA axis activation, interact with steroid receptors expressed throughout the brain that functions primarily as transcription factors to regulate cellular function beyond the time scale of acute stress effects”, (pp. 2-3). This whole process drives the behavioral response a person experiences. However, the exact effect of this relationship between HPA and resilience is unclear. 

In the same area, Dehydroepiandrosterone (DHEA) is released, along with cortisol, in response to stress. Russo, Murrough, Han, Charney & Nestler (2012) propose that current research about DHEA suggests that it counter’s the negative effects by producing an anti-inflammatory response, (p. 1476). “It has been reported that DHEA responses to adrenocorticotropic hormone (ACTH) were elevated in PTSD and negatively correlated with the severity of symptoms, suggesting that DHEA release during stress may buffer the severity of PTSD”, (p. 3). Oddly, the hormone DHEA released during stress can actually help alleviate the negative response.

Testosterone is released in response to stress is considered to serve as a pro-resilience hormone creating a positive mood and connectedness, and important among sports team members. Interestingly, after the experience of a stress event, testosterone levels decrease for a period of time. "...Early studies in men suggest that testosterone may be effective in treatment–resistant depression and as an adjunct to SSRI treatment..."  (p. 3).

“it seems clear that moderate degrees of stress exposures during early life, adolescence, and adulthood can shift an individual’s stress…by increasing the range of tolerable stress for the organism”, (p. 7). These early exposures possibly prime the HPA axis to function more efficiently; producing moderate levels of hormones released thus allowing for less impact and more recovery. These findings and further research outcomes can have significant clinical implications for future treatments. "...far more insight is needed into the genetic, epigenetic,neurobiological, and neuroendocrine basis of sex differences in stress susceptibility vs. resilience. Finally, we need to better define how just the right type and level of stress inoculation, through this complex interplay of mechanisms, can promote resilience..."

References
Russo, S. J., Murrough, J. W., Han, M. H., Charney, D. S., & Nestler, E. J. (2012). Neurobiology of resilience. Nature neuroscience. Volume 15(11); pp. 1475-1484. Doi:10.1038/nn.3234.

Found online: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3580862/
Link to article: .http://www.nature.com/neuro/journal/v15/n11/abs/nn.3234.html