Katie Couric's Notebook: Surviving disaster

It was just one in a flood of news reports pouring out of Japan: 

An elderly man sitting on the ground, surrounded by rubble, on the spot where he saw his wife swept away by the tsunami. "I am thinking that I might have closure if I keep sitting here," he said.

Complete Coverage: Disaster in Japan

He wasn't crying or screaming. In fact, he seemed almost numb. That's one symptom of acute stress disorder, explained Dr. David Spiegel, a professor of psychiatry at Stanford University. Others include jumpiness, irritability and flashbacks, all of which can morph into PTSD.

Dr. Spiegel suspects that much of the country is now suffering from these symptoms, made worse by the continuing aftershocks and threat of radiation. The survivors will fare better if they talk about what happened, he said, and try to reconnect with neighbors and friends.

But for now, many Japanese are like that old man - silently searching for the lives they lost in an instant.

That's a page from my notebook.

I'm Katie Couric, CBS News.