A closer look at PTSD

We know 39-year-old Major Nidal Malik Hasan was a psychiatrist.  He worked with soldiers returning from war. But could this man, who never served a day in combat, have developed Post Traumatic Stress Disorder (PTSD) by living through his patients accounts?

"Unlikely," said Dr. David Spiegel, a Psychiatrist with Eastern Virginia Medical School (EVMS) Health Services.

Dr. Spiegel used the events of 9/11 as an example. He says people developed PTSD from watching the events of that day replayed over and over on television. But, he says, "it's very unlikely someone could develop it by treating it he said."

Spiegel says the "first criteria for PTSD is to kind of respond, in fear or horror."

It's more likely that Hasan, who'd been given orders to deploy to Afghanistan, would be scared and anxious -- both normal, natural reactions, according to Spiegel. But there's nothing normal or natural about what he's accused of: taking two guns and opening fire on an innocent, unsuspecting crowd.

"I think this gentleman, without knowing much about him, probably had cultural beliefs that factored into what was going on."

Dr. Spiegel explained, while it may be easier to believe Hasan is mentally ill, it would be rare to have a first episode at age 39. Most mental illness comes to light in a person's late teens or early 20s, making hard to accept that Hasan may have never had a mental illness.