Numerous studies have been conducted in an attempt to identify the specific factors that may increase risk for PTSD. For example, people may be more likely to develop PTSD following the experience of a traumatic event if, for example, they have experienced multiple traumatic events in their lifetime, have a history of psychological difficulties, and have limited social support available to them.
A family history of psychological difficulties may also increase a person's likelihood of developing PTSD after experiencing a traumatic event. A study by Dr. Rachel Yehuda and colleagues, published in the Archives of General Psychiatry, examined why this might occur. Specifically, the researchers examined the cortisol levels of 33 adult children of Holocaust survivors with and without PTSD.
Cortisol Levels and Vulnerability to PTSD
Cortisol is a hormone that is released by the adrenal gland, thanks to messaging from the brain, in response to stress. Cortisol is very important as it essentially mobilizes a person action to take action to protect himself when a threat is present (the "fight or flight" response). In addition, cortisol helps to prevent or turn off other stress-related bodily responses, such as the part of our nervous system that is responsible for the experience of arousal, such as increased heart rate.
Researchers have found that people who have lower levels of cortisol after experiencing a traumatic event may be at greater risk for developing PTSD (a surprising finding, as levels are actually elevated in those with major depressive disorder -- a condition that shares many symptoms with PTSD.)
Low cortisol levels may be a sign that a person's body may not be able to easily turn off certain stress-related reactions. Consequently, a person may experience physical and psychological distress for a longer period of time after the experience of a traumatic event, promoting the development of PTSD.
This research suggests that cortisol levels may be a good indicator of who may be more vulnerable to developing PTSD following a traumatic event (particularly low cortisol levels). It was for this reason that the researchers focused their attention on cortisol levels in this study.
What They Found
The adult children of Holocaust survivors with PTSD were generally found to have lower cortisol levels than the children of Holocaust survivors without PTSD. Cortisol levels were also related to the severity of the parent's PTSD -- the more severe the parent's PTSD, the lower the child's cortisol levels. In addition, low cortisol levels seemed to be particularly related to whether or not the child's mother had PTSD. It did not, however, appear as though having two parents with PTSD further increased the likelihood that their children would have low cortisol levels.
What Does This Mean?
The findings from this study suggest that children who have parents with PTSD may actually be more vulnerable for the development of PTSD themselves, and this vulnerability may be due to having lower cortisol levels. PTSD may influence the ways in which a parent interacts with his or her child; it was also suggested that this may cause brain changes early in life that promote low cortisol levels.
These findings speak to the importance of seeking out treatment for PTSD, especially if you are someone who has a child or is expecting a child. There are a number of resources available for those with PTSD through many different organizations, such as the Anxiety Disorder Association of America and the National Alliance on Mental Illness. These organizations offer a number of resources, including information on treatment options available across the country.
It is important to point out that even though someone may be vulnerable to PTSD, it does not mean that PTSD will definitely develop following a traumatic event. There are a number of ways individuals vulnerable to PTSD can reduce the likelihood of developing PTSD after a traumatic event, such as by seeking out support and connecting with others, using healthy coping skills, and getting treatment.
Sources:
Delahanty, D.L., Raimonde, A.J., Spoonster, E., & Cullado, M. (2003). Injury severity, prior trauma history, urinary cortisol levels, and acute PTSD in motor vehicle accident victims. Journal of Anxiety Disorders, 17, 149-164.
Raison, C.L., & Miller, A.H. (2003). When not enough is too much: The role of insufficient glucocorticoid signaling in pathophysiology of stress-related disorders. American Journal of Psychiatry, 160, 1554-1565.
Yehuda, R. (2002). Current status of cortisol findings in post-traumatic stress disorder. Psychiatric Clinics of North America, 25, 341-368.
Yehuda, R., Teicher, M.H., Seckl, J.R., Grossman, R.A., Morris, A., & Bierer, L.M. (2007). Parental posttraumatic stress disorder as a vulnerability factor for low cortisol trait in offspring of Holocaust survivors. Archives of General Psychiatry, 64, 1040-1048.
