When he entered a Silver Spring bank on Feb. 9, 1977, shouting "this is not a holdup," Vietnam veteran Stephen W. Gregory said he thoughthe was "back in the Nam;" and as he shot at the walls and the air ducts he felt "the Viet Cong were coming to get me."

The holding of eight hostages at riflepoint for six hours on that day, Gregory says, signaled the breaking point for him. In the eight years since the dicorated veteran was discharged from the Marine Corps, his life had become almost a series of fights and personal defeats interspersed with flashbacks of his war experiences.

Even this weekend, as he sat passively in a T-shirt and jeans in his parent's living room, discussing a judge's decision to release him from prison, the conversation shifted back to the combat zones and the old faces of Vietnam.

He says he thinks there is a "special heaven" for all the Vietnamese people whose faces he saw shot off in the war. He says he still feels responsible for the six-year-old Vietnamese child he befriended, but who was later killed, he said, because of her association with American soldiers.

For eight years, Gregory says he carried around those memories, as his parents and others tried to persuade him to forget them, thinking, "I was alone."

Gregory, 29, has become a symbol among Vietnam veterans groups of the delayed psychological trauma that psychiatrists and psychologists say they are begining to discover in combat veterans of the Vietman war.

And his is one of the first court cases in which defense attorneys have been able to argue that irrational, criminal behavior in the veterans is linked to this trauma.

As a condition of releasing him on probation for the bank takeover, and instead of sending him to jail for six years as prosecutors had asked, Montgomery County Circuit Court Judge John J. Mitchell ordered Gregory to begin receiving therapy at the veterans hospital in Perry Point, Md.

Gregory said that initially, he was merely interested in getting psychological help for himself, but now, he says he feels his case will inspire other suffering Vietnam veterans to "come out of the closet and seek help."

Gregory says he also thinks his case will help persuade Congress to earmark more funds to aid Vietnam veterans.

From his youth, Gregory says he always craved attention.That is why, he says, he ran away from home 15 times as a teen-ager.

When he was 17, Gregory, a high school drop-out who later earned an equivalency diploma through the prison system, enlisted in the Marine Corps after he was brought up on charges of resisting arrest, disordely conduct, and carring a conceled weapon -- a pen knife.

The judge in the case gave him the choice of going to prison of joining the military.

At 18, he was shipped to Vietnam. On his first day out, he said, his company was under constant fire. On the second day, he saw 14 of his platoon comrades brought in from the field, dead. He saw his best friend's body devastated by bullets and shrapnel in the middle of a combat zone.

And yet, Gregory achieved a measure of acclaim that he had never known in his adolescence. He received eight citations during the war, including the Bronze Star and Purple Heart. Gregory, who was wounded in the head by shrapnel. took only three days off in his year-long tour of combat duty, because he had become known as the "good luck charm" for his squad.

Three months after he left, all the men in his platoon were either killed or wounded in a night ambush, he said.

When he returned home to Maryland, he wore his war medals. But his family and just about everyone else, he said, told him, "you've got to forget."

Gregory said he felt incapable of becoming close friends with other men because "they reminded me of my dead friends." He couldn't stand being around other combat veterans "because of all the things we knew" about the war.

By the time he entered the Citizens Bank and Trust Co. of Silver Spring, wearing sunglasses and a business suit, Gregory had been divorced, had a daughter he was never allowed to see, been involved in numerous brawls, and had injured his father in a fight, according to court records.

He was discouraged with the series of bill collector's jobs he had held, and in one way or another, lost. He was depressever having just been turned down for a more promising job with a Glen Burnie corporation. He blamed it on the fact that the Marines refused to give him an honorable discharge, because once, while on leave, he assaulted a man who he said called him "soldier boy" and made "snide remarks" about the Marines.

He attempted suicide three times, he said.

Dr. Stephen Sonnenberg, a psychiatrist who examined Gregory, maintained that Gregory was really trying to commit suicide by taking over the bank.

Gregory, he said, was suffering from a psychological illness that produces suicidal tendencies and guilt feelings in persons who have seen a great deal of death and destruction, but survived it all.

Gregory eventually released the hostages unharmed and gave himself up to police. His case originally was tried in August 1977. His conviction was overturned on appeal and Gregory pleaded guilty to the same charges last January.