Often stress-related disorders are linked to individuals who work in the firing line. In an investigation led by Dr. Charles Marmar, professor and chair of the Department of Psychiatry at the NYU Langone Medical Center in collaboration with the San Francisco VA Medical Center and the University of California, San Francisco, the researchers examined police recruits during academy training prior to critical incident exposure. They provided the recruits with salivary cortisol at first awakening and after 30 minutes. According to the study results, recruits with the greatest increase of the stress hormone cortisol after awakening were more likely to display acute stress symptoms in response to trauma years later as police officers.

The investigation is one of the largest to identify a potential technique for predicting vulnerability to stress either during or following a traumatic experience. Results of this investigation are published in the December, 2011 issue of Biological Psychiatry.

Dr. Marmar, explained:

“This study is significant as a potential indicator in determining when people may exhibit stress symptoms in the future. Few studies have prospectively examined the relationship among pre-exposure hypothalamic-pituitary-adrenal activity, acute stress reactions and post-traumatic stress disorder (PTSD). The findings may lead us to new insights on how to identify those who are at a higher risk of PTSD.”

The 296 police recruits enrolled in the study had their cortisol levels measured after waking up and again 30 minutes later. The difference between the two levels is known as cortisol awakening response (CAR). The researchers discovered the greater CAR during academy training predicted greater peritraumatic dissociation and acute stress disorder symptoms over the initial 3 years of police service.

The study showed that stronger CAR predicted two particular stress responses. In one the person was dissociated, experiencing the traumatic event in a dreamlike state of unreality, and in the other, the individuals showed acute stress disorder symptoms following the event, such as increased heart rate, faster breathing, intrusive memories of the event and conscious avoidance of thoughts or feelings related to the event.

Dr. Marmar, stated:

“This research is just the tip of the iceberg. We need additional studies to determine if early identification of these risk factors will result in intervention which could help reduce or minimize the long-term effects of trauma exposure.”

Written by Grace Rattue