He leads the sort of life that thousands of young men women dream of leading when they leave their home towns all over America and come to work in the nation's capital.

He knows and is known by decision makers at both ends of Pennsylvania Avenue, where his advice is sought and listened to. He attends the right parties and sometimes gives them, and he enjoys the companionship of abright, attractive, career woman.

The Christmans season should a high spot in the year for him. But it is not. For Christmas reminds him of his Norman Rockwell Christmases with the midwestern family he at once longs for and is slightly ashamed of.

But he can't go home again, or feels he can't, because he no longer understands the life style of his parents, and they have never understood or approved of the life he now leads.

For him, as for thousands of people in the Washington area, many of them single but some surrounded by family, the year ends on a sour note.

The forced joyousness of the season, say psychiatrists and mental health professionals, reminds people that others have happy family lives, while they do not, or others are succeeding in careers, while they are not, or last year they were with loved ones, and this year they are not.

Washington are psychiatrists and hotline workers deal with these people, but much less frequently than is widely believed. For rather than flood hotlines with phone calls, many people keep their depression to themselves, toughing it out until Jan 2. when life returns to normal.

But mental health experts agree that the problem is a serous one for thousands of persons, like the young woman who told a reporter that Christmas was always a time of family gatherings, a time when she and her three sisters would come home to their mother, the mainstay of the family.

But three years ago their mother died, and now "Christmas is the pits, it's unbearable. We go home, but home isn't the same. We exchange presents, ask how each other are, and then leave. Nobody wants to stretch it out pretending to be happy."

Because it was such a happy time, Christmas is now the woman's reminder that such times are gone forever. "It makes me feel like I'm a different person from the one I was," she laments.

"The problem isn't treatable depression, or people who seek treatment, it's the pointed aloneness of people," said Dr. Dorothy Starr, a District psychiatrist, who view the problem of holiday depression as serious, although "overrated."

"What do you say people," Starr asked rhetorically," when they ask if the children are children are coming home and the children are both strung out on drugs somewhere? Or people ask if you're going home and you don't have a home where you're welcome?"

"There are a lot of single, professional, women who desperately want to be in relationships at this time (of year), the Bing Crosby image of being in front of the fire for Christmas," said Lawrence Snak, a clinical psychologist who heads the mental health services for Geogre Washington University's 15,000 member health maintenance organization.

"So what do they do for the holidays?" he continued. "They wish desparately that the holidays would go away.'

Christmas carols and songs alone are enough to make a slightly depressed person positively morose.'Tis the season to be jolly! Joy to the world! Oh, what fun it is to . . . Oh tidings of comfort and joy, comfort and joy! But for the lonely single, the divorced or separated parent, this passage from "We Three Kings" may be more apropos:

"Myrrh is mine, its bitter perfume Breaths of life, of gathering gloom; Sorrowing, sighing, bleeding, dying sealed in a stone cold tomb . . . "

The victim of holiday depression, said Sank, "might be a middle aged man who is separated and missing the sense of being able to gohome for the holidays and having the kids around him. They may be home with their mother, and what is there for him? He's got his work and maybe he's dating."

According to Sank and Dr. Daniel Patterson, a psychiatrist for the 110,000 member Group Health Association, there is a slight increase in psyshiatric visits at holiday time, but they are usually one-time visits, or calls from persons depressed by the holidays.

These cries for help are often offset, said Patterson, by a decrease invisits from people in ongoing psychotherapy, and who are distracted from their usual problems by the bustle of holiday preparations.

There is a lot of general depression at holiday times, said Patterson, because "holidays are stress points. They're times of financial stress, travel, entertainment, and the sheer work of being jolly for 10 days."

Another cause of so-called holiday depression is the fact that Christmas often fails to live up to our expectations of it. "After the holidays are over people find that they weren't what they expected, so depression carries over into January," said Harriet Guttenberg, director of the Montgomery Country Hotline and head of the Washington Area Hotline Association.

According to Guttenberg, hotline calls begin to build up in October and stay at a high level right through the winter. Christmas, she says, does not seem to generate "that many more calls."

The one hotline that does get in-undated during the Christmas season is the Holiday Hotline run by the Washington Area Council on Alcoholism and Drug Abuse (WACADA). "WE'RE GOING TO GET 2500 CALLS IN A 13-DAY PERIOD," SAID MARY SPENCER, WACADA'S DIRECTOR OF TRAINING, "BUT WE GET THOSE CALLS BECAUSE WE HAVE A LOT OF PUBLIC SERVICE SPOTS ON TELEVISION AND THE NEWSPAPERS DO STORIES."

MOST OF THE CALLS WACADA receives "involve alcoholism," said Spencer, and experts say the holiday season is particularly hard on alcoholics because there is so much social pressure to consume it.

"Christmas is the only time of year when it's okay for everyone to drink," said Spencer. "People don't fuss with the alcoholic during the holidays. When the alcoholic causes a problem is at the end of the holidays, when everyone else stops drinking and the alocholic can't," he said.

Part of the myth of holiday depression is that the suicide rate skyrockets at Christmas time. But it simply isn't so, at least not in Washington.

In fact, according to D.C. Medical Examiner Dr. James Luke, the suicide rate the past several Decembers has been lower than that for other months. "I've heard about holiday suicide," said Luke," but we just don't seem to see it."