Transgenerational Transmission of PTSD
At a recent scientific meeting, Rachael Yehada showed that PTSD-like traits could be passed transgenerationally. Mothers in New York City who were pregnant on September 11, 2001 and developed post-traumatic stress disorder (PTSD) produced children with low cortisol in their blood (a sign of PTSD). If the fathers had PTSD during the mother’s pregnancy, the children had high cortisol.
These gender-related findings have some parallels in studies of rodents. When a rat pup is separated from its mother for 15 minutes, the mother is overjoyed to see the pup return and licks and grooms it excessively. This maternal overprotection yields an animal with lifelong low cortisol through an epigenetic process. The glucocorticoid receptor gives a feedback message to suppress cortisol, and glucocorticoid receptors are increased in the pups’ brains because of lower methylation of the DNA promoter for glucocorticoid receptors.
If a father has PTSD, there is more methylation of the promoter for glucocorticoid receptors and less expression of them in the forebrain. There is also less feedback suppression of cortisol and the baby exhibits high cortisol.
The methylation of the glucocorticoid receptors in the offspring’s white blood cells is highly correlated (r=0.57, p<0.005, n=23) with methylation in the parent’s white blood cells.
