Jerry Parker has spent the last three weeks in the vacant houses and gravel pits of Suitland, drinking by day and hiding at night from teen-agers who have robbed and beaten him.

A former mental patient with severe emotional problems, he is 25, broke, and terrified after being evicted from what was his home for almost a year; a filthy, roach-in-fested, three-bedroom apartment in Suitland that he shared with 10 other persons.

"I've had to spend nights camping in the woods and drinking by myself, all alone," Parker said in an interview. "I've got no place else to go. It's confusion and chaos and hell. It scares me."

In an earlier era of health care, Parker, whose name has been changed for this story, might have spent his life in an institution. Instead, because doctors believe he can survive with hekp in the community, he has repeatedly been discharged from mental hospitals, and has spent most of the last five-years in crowded and dirty apartments, in the basements of friends' houses, on the streets of Suitland, or in jail.

According to local and state officials, Parker's case is not unique. Each year, thousands of persons in Maryland are released from state mental hospitals not because they are cured, but because it is hoped that they can live in their communities with the help of families and local health services.

Too often, however, state and local officials say, persons like Parker are found in the streets, too "normal" for the state institutions, too trouble to be adequately helped in the community, and too poor to afford private care.

"That's a very typical situation," said Prince George's County Health Officer Donal K. Wallace, speaking of Parker. "There's definitely a real gap in the entire delivery system. People in society don't want people like around them, and families don't want to take care of them anymore."

In Parker's case, life in the community has only worsened his problems, according to his closest friends.

"He's gotten much worse in the last few years," said Jane Reber, who was Parker's foster mother during his childhood. "He talks to himself now-which he never used to do-and he's much wider. He's become less and less able to take care of himself and manag."

In an interview, Parker said that he smokes as many as 20 pipes of marijuana a day, and takes other drugs to relieve his frequent depressions.

According to Reber and other close friends, Parker has frequently attempted or threatened suicide simply to gain admission to a bed-and a place to stay-at Prince George's General Hospital.

"I'm very worried about him, but I don't know what I can do anymore," said Reber. "I've been in this situation 35 or 40 times: I come home and there's Jerry on my doorstep with no place to go. I can't handle him any longer. I've just given up."

"..everyone keeps telling him, 'Come on, Jerry, be normal, come on, be like me,'" Reber said. "They don't understand that he can't be that way-that he'll never be that way."

Persons who know Parker will say his life has been filled with continual, frustrating, and ultimately unsuccessful efforts by himself and others to find adequate care for his problems.

Reber said that Parker was turned over to an orphanage by his mother when he was only a few months old. Reber became his foster mother when he was 4 1/2, after, he was released from Children's Convalescent Hospital in Washington, where was already being treated for severe emotional problems.

As he grew older, Reber said, Parker, who has a near-normal I.Q., learned to speak, read, and take care of himself, but school was always a problem.

"He was in special education from second grade on," she said. "In second grade he was hard to control, so they used to keep him in the hall, surrounded by filing cabinets, for days. He would just stand there and kick at them all day, with nobody paying any attention."

When he was 13, Parker's foster father decided to have moved from home because of his problems. Within four years, he was shunted to the District of Columbia's Junior Village, an institution for homeless youths, then to a group home in Virginia, and finally to an orphanage in Baltimore.

Nothing worked. "He was treated badly," Reber said. "They took him out of school and took him off his medicatrion. He tried to commit suicide twice when he was in Baltimore. Eventually they had to transfer him back to St. Elizabeths mental hospital in D.C. From there, he came back to live with me."

That was in the early 1970s. Both Parker and his friends describe what followed as the best years of his life so far. He was enrolled at a special program at Suitland Senior High School under which he received credit, and eventually a high school diploma, for working in a drug store.

At 18, however, Parker once again became a victim of local health systems. Foster care payments to Reber were cut off because of Parker's age, and Reber, suffering financially, asked him to move out.

Soon afterward, Parker lost his job at the drugstone after he tried, ineptly, to steal cigarettes. Since them, his life has become a series of moves, new jobs, slip-ups, fresh starts, and collapses.

"He's really not very capable of managing his own affairs," said Bill Moran, an special education teacher who counseled Parker during his high school years. "He doesn't get much money, and then he wastes it away on cigarettes, junk food or alcohol and drugs.

"He keeps having trouble with his jobs and apartment because of the pot, and because he steals now. He steals stupid things-like pocket lighters or shampoo-and he usually steals from people he knows, because he feels safter that way."At one time or anothe over the last four years, Parker has been tossed out of county mental health units, stores and restaurants in Suitland, several apartment, his foster mother's house, a halfway house in Virginia, and out of the psychiatric wards of three hospitals, according to Moran and Reber.

He spent most of one winter in Spring Grove state hospital, in Catonsville, Md., and part of another winter in the psychiatric ward of Prince George's general Hospital. "I think the doctors just signed him in because they felt sorry for him," said Moran. "He had no place else to go."

At one time, Parker was enrolled in the county's vocational rehabilitation program, and ended up working in a job training program, where he was paid 50 cents an hour for a 30-hour week. He quit after four weeks because he said he wasn't paid enough.

All the while, Parker has been a client of Family Services Inc., a non-profit group with a state contrat to care and help find housing for released mental patients in Prince George's.

Moran said Family Services has stopped recommending housing for Parker because he has been evicted from two apartments after a series of disturbances. Meanwhile Parker has only sporadically attended Family Services' therapy sessions, and has frustrated his caseworkers by altering drug prescriptions they provide him for his illness.

Officials of Family Services and Spring Grove hospital said they could not discuss Parker's case with a reporter because of confidentiality requirements.

Last year, in desperation, Reber went to court to have Parker declared unable to protect himself under Maryland's Protective Services Act, passed in 1977. The act provides for county departments of social service to take charge of persons who are declared incapable of managing their own affairs.

According to state health officials, funds were never allocated to carry out the program, and only a few staff workers in each county are assigned to work on protective service cases. According to Reber and Moran, the Prince George's County Department of Social Services has not yet discovered Parker, although the court declared him unable to protect himself and issued an order that he be cared for.

Meanwhile, in the last year, Parker's problems have grown worse. He was convicted and placed on probation last year for stealing shirts from a Hyattsville store. Then, last month, he was arrested again, this time on a charged of stealing $15 in checks from the mailbox of his foster mother's husband. That case is pending.

"It's not really the fault of Family Services and these local health agencies," said Moran. "Jerry's almost impossible to work with. He needs a halfway house or some kind of structured environment where he can have a job or a home, and yet have somebody manage his affairs and keep him out of trouble. Unless you're rich, there just isn't an arrangement like that available.

"For the rest of life, he may be so severely handicapped that he can't produce much or make that much of a contribution to society. But the question the county has to face and the society has to face is whether to lock him up or let him die because of that," Moran said.

Parker, meanwhile, has more modest wishes for his life. "I would ideally like to have a job and make money." "I would like to have an apartment, and save money until I can buy a stereo and a car, a small car. I want the usual things."