Predisposed to PTSD

According to some estimates, more than half of us will experience a
traumatic event in our lifetime: A serious car accident, a physical
assault, combat duty during wartime. Yet relatively few will develop the
nightmares and panic attacks of post-traumatic stress disorder, or PTSD.
Why some and not others? "We don't walk into trauma equally, so we don't
all come out of it equally," explained Rachel Yehuda.

A neuroscientist at the Mount Sinai School of Medicine, Yehuda
noted there are a number of risk factors for PSTD, including previous
trauma, childhood abuse, and a family history of pathologies such as
alcoholism and depression. Her own research on cortisol, a hormone
secreted by the adrenal gland in times of stress, has raised another
possibility that a biological vulnerability to PTSD might actually be
inherited. Although PSTD patients have suffered severe stress, they have
lower-than-average levels of cortisol in their blood. Yehuda said she thinks she
may have the solution to this puzzle: Low cortisol levels may themselves
be a risk factor for PTSD.

She cited studies that show that people who had low cortisol levels
immediately after being in a car accident were more likely to develop
PTSD down the road, and that adult children of PSTD-stricken Holocaust
survivors have low cortisol levels. These sons and daugthers may be at
high risk of developing the disorder, says Yehuda—but should disaster
strike, a blood test may one day single them out for special
treatment.