Traveling in Mexico and observing the operation of Mexican families has brought a simple question to my mind: Why are Mexican-American soldiers from the Iraq War significantly more susceptible than other ethnicities for developing post-traumatic stress disorders (PTSDs)? Does their “weakness” reflect genetic contributions to their risk for PTSD, or, more likely perhaps, does it stem from differences in family structure and child-rearing?

Susceptibility to PTSD is going to be an on-and-off subject on this blog for awhile. We’re going to figure it out — because susceptibility will tell us important things about the plastic change in the brain that underlie this devastating condition.