Hundreds of firefighters and emergency medical workers who responded to the World Trade Center attack have reported nightmares, sudden anger and other psychological symptoms so severe that they were taken off active duty.

The 14,000-member Fire Department said it has put about 350 people with stress-related problems on light duty or medical leave since Sept. 11.

Nearly 2,000 more firefighters, fire officers and workers in the department's Emergency Medical Service unit have seen a counselor since Sept. 11 through the FDNY's counseling services unit.

The number is unexpectedly large for an institution that traditionally prefers to handle problems within the close-knit firehouse fraternity.

"Few people would have predicted as many firefighters would come forward looking for help," said Terence Keane, a counseling unit consultant who heads the National Center for Post-Traumatic Stress Disorder in Boston.

Firefighters say the staggering losses of Sept. 11 changed perceptions of the counseling unit, once seen as only for those with drug or alcohol problems. The department lost 343 members when the Twin Towers collapsed.

"Before this, guys would not even dream of going to counseling," said 10-year firefighter Vinny Picciano, who sees a counselor once a week. "Now, the guys that are coming down, they realize something is wrong. Guys are hurting."

Of the 350 placed on light duty or medical leave, 100 remained off the active roster as of Wednesday. Many others have retired and some have returned to work.

The department is working firefighters overtime to absorb the loss. The department expects to spend as much as $170 million on overtime this fiscal year, roughly double its previous amount, spokesman Frank Gribbon said.

The counseling unit saw approximately 600 people in 2000. Its staff, which had 11 counselors and clinicians, is now five times larger.

About one-fifth of those in counseling suffer from post-traumatic stress disorder, a severe reaction that can require intensive counseling and medication, counseling services unit director Malachy Corrigan said.

The remaining 80 percent are experiencing acute stress disorder, a milder reaction that can improve after as little as a month of treatment.

Firefighters' Sept. 11 experiences prompted feelings of powerlessness and terror in people used to controlling their own fears.

"Their coping skills are breaking down," Corrigan said.

Counselors are encouraging firefighters to retell the stories of their Sept. 11 experiences as a way to regain control.

"There's a lot of people who won't tell their stories to their wives because they don't want to make their wives more nervous," Corrigan said. "What you're doing is helping people regain some mental mastery of the situation."

The Police Department required every member to attend a half-day stress management education class after Sept. 11. The Fire Department took a different tack -- providing one-on-one counseling, but leaving the choice of whether to seek help to the individual.

Those who chose counseling have benefited from the individual attention, said Tom Manley, health and safety officer for the firefighters union. "Doing it in a group setting, you're not really going to get what you need out of it," he said.

Picciano said he expects to recover from the back and neck injuries he suffered when he was hit by debris from the collapse of the south tower.

As for his psychological wounds, he said he still imagines loud noises at night and his dreams are haunted by images of people leaping from the burning trade center. He said he sees pieces of bodies on the sidewalk and cannot fall back to sleep.

"I lost a lot of friends. I lost a lot of guys. It's killing me just thinking about that," he said. "I never want to be that vulnerable again."

The counseling unit soon will try to gauge the depth and breadth of the department's psychological needs with the largest-ever survey of an emergency department's response to trauma.

Every Fire Department member will be asked every three to six months to fill out a pages-long survey. The survey, developed by the counseling unit and academic and government experts, is expected to continue for years.