Hurricane Katrina survivors bound to suffer trauma

Many survivors of Hurricane Katrina will suffer significant psychological trauma, some experts say.

But they also stress that people are remarkably resilient, and that most who survived the storm won't be permanently impaired.

"I would expect to see most people recover and be fine," said psychologist Andrew Baum of the University of Pittsburgh, who studies reactions to disasters. "People do better than we expect them to."

It will lead to "ordinary reactions to extraordinary events," as Gerard Jacobs, director of the Disaster Mental Health Institute at the University of South Dakota, puts it.

Reactions such as anxiety. Anger. Depression. Trouble concentrating and remembering things. Nightmares. Headaches. Withdrawal from other people and activities.

Some of the survivors could develop post-traumatic stress disorder, a long-term reaction that includes flashbacks and intrusive thoughts.

Barry Hong, a psychiatry professor at Washington University School of Medicine in St Louis, who has studied flood survivors, said he'd guess that maybe half the survivors might need counselling or other formal psychological treatment, while the other half may do fine on their own with help from family and friends.