By BENEDICT CAREY

The New York Times

The mental-health fallout from the Sept. 11 attacks has taught psychologists far more about their field's limits than about their potential to shape and predict behavior, according to a new review.

The review, a collection of articles due to be published next month in a special issue of the journal American Psychologist, relates a succession of humbling missteps after the attacks.

Experts greatly overestimated the number of people in New York who would experience emotional distress. They rushed in to soothe victims using methods that proved to be harmful to some.

And they fell to arguing over whether watching an event on television could produce the same kind of traumatic reaction as being there.

These and other developments have changed the way mental-health workers respond to traumatic events, said Roxane Cohen Silver, a psychologist at the University of California, Irvine, who oversaw the special issue along with editors at the journal.

"You have to understand," she said, "that before 9/11 we didn't have any good way to estimate the response to something like this other than — well, estimates" based on earthquakes and other trauma.

Eager to help

Chaos reigned in the New York area after the World Trade Center towers fell. Therapists by the dozens volunteered their services, eager to relieve the suffering of anyone who looked stricken.

Freudian analysts installed themselves at fire stations, unbidden and unpaid, to help firefighters. Employee-assistance programs offered free therapy, warning of the consequences of letting people grieve on their own.

Some of those given treatment benefited, the review found, but others became annoyed or more upset. At least one commentator referred to therapists' response as "trauma tourism."

"We did a case study in New York and couldn't really tell if people had been helped by the providers, but the providers felt great about it," said Patricia Watson, a co-author of one of the journal's articles and associate director of the terrorism and disaster programs at the National Center for Child Traumatic Stress.

"It makes sense; we know that altruism makes people feel better," Watson said.

Researchers discovered the standard approach at the time, in which the therapist urges a distressed person to talk through the experience and emotions, backfires for many people. They plunge even deeper into anxiety and depression when forced to relive the mayhem.

Crisis-response teams now take a much less intense approach called psychological first aid, teaching basic coping skills and having victims recount their experience only if it seems to help.

Limits to debriefing

One of the biggest lessons of Sept. 11, said Richard McNally, a psychologist at Harvard University who did not contribute to the review, was that it "brought attention to the limitations of this debriefing."

Another, he said, was that it drove home the fact that people are far more resilient than experts thought.

No one disputes that thousands who lost loved ones or fled from the collapsing skyscrapers are living with deep emotional wounds. Yet estimates after the attack projected epidemic levels of post-traumatic stress disorder (PTSD), afflicting perhaps 100,000 people, or 35 percent of those exposed to the attack in one way or another.

Later studies found rates closer to 10 percent for first responders, and lower for other New Yorkers. The prevalence in children was slightly higher.

"Some of us were making this case about resilience well before 9/11, but what the attack did was bring a lot more attention to it," said George Bonanno, a psychology professor at Columbia University.

It also stirred a debate that may change the definition of post-traumatic stress.

In the weeks and months after the attack, experts and news articles warned that people around the country and perhaps the world who had no direct connection to the attacks would also develop diagnosable symptoms, merely from seeing the images on a television screen.

Silver, who was among the first to question overestimates of trauma, has found evidence for such effects in her own studies.

"The distress spilled over the outside communities, mostly to people who saw the images and had pre-existing psychological problems," she said. "The numbers are low, but I think the data is convincing."

McNally, among others, disagrees.

"The notion that TV caused PTSD seems absurd," he said in an email.

The editors of the Diagnostic and Statistical Manual, the so-called encyclopedia of mental disorders compiled by the American Psychiatric Association, are debating whether to change the criteria for post-traumatic stress to exclude such at-a-distance cases.

The new report reviews hundreds of other types of Sept. 11 studies, political and social. Americans on average became more prejudiced toward Arabs after the attack, more likely to contribute to charities and more supportive of aggressive government action against suspected terrorists.

No new theories

But these and other findings were not new; studies after previous attacks in other countries found similar reactions. For all its fury and devastation, 9/11 gave rise to no new theories of behavior, no new therapies.

Instead, some authors said, its chief effect on the social sciences was to caution against applying theories so readily to real life.

Another author in the new collection, Philip Tetlock, a psychologist at the University of Pennsylvania's Wharton School, notes that intelligence agencies use scientists to try to predict the behavior of foreign leaders and terrorists — and their track record has been decidedly mixed.

"The closer scientists come to applying their favorite abstractions to real-world problems," the article concludes, "the harder it becomes to keep track of the inevitably numerous variables and to resist premature closure on desired conclusions."