It took four years of goading before Charles Lum managed to provoke his first psychotherapist into dumping him.

"She was afraid of me,"

Lum recalls. "She had a nervous tic and I would bait her until I got that tic going."

After that, no therapist at the D.C. Institute of Mental Hygiene wanted to take on Lum. Obese and hypercritical, Lum, 52, a government printer, has spent much of his life finding fault and raging against his wife, nine children and his own body. When he's angry or frustrated, he often gets sick. He has been hospitalized for an impacted gall blader, fluid buildup in his chest, stomach ulcers, varicosities of the esophagus and cirrhosis of the liver, and more than a dozen times for cellulitis, an inflammation that has swollen and blackened the flesh of his lower legs.

Five years ago, Dr. Harold Eist, who runs the D.C. Institute, accepted Lum as a patient. Eist, who has diagnosed Lum as having "borderline personality disorder with paranoid-depressive and psychosomatic features," now sees his patient once a week.

"He was, at first, an impossible person, bombastic, explosive, attacking," says Eist. "But I've always found something likable in him."

Last fall, Lum, whose oldest son was killed in Vietnam, went to the Mall to look at the Vietnam War memorial. He got into an argument there with an official from the U.S. Park Service.

At his next therapy session, Eist says Lum "tried to pick a fight with me. He got very nasty. But I hollered back at him: 'I'm your doctor, not your public toilet.' He broke down and started talking about how he blamed himself for the death of his son."

Lum grew up in a working-class Catholic family in New York. He did not graduate from high school, and is now a GS12, making $35,000 a year.

He went to the institute nine years ago only "to satisfy" a doctor and priest who were alarmed by the apparent link between Lum's emotional outbursts and his illnesses. After nearly a decade of going to the clinic, he still keeps his therapy secret from everyone but his family and closest friends.

"A guy worries," he says, "about being branded crazy or something."

As a federal worker, Lum is covered by Blue Cross-Blue Shield insurance for 75 percent of the cost of up to 50 sessions of psychotherapy a year. Because of his income and insurance, the institute charges him $50 a session, its highest rate.

After five years of therapy, Eist now believes the roots of Lum's problems lie in his childhood. Lum says he has begun to make peace with angry memories of his father.

"I was very defiant with my father." says Lum. "If I wasn't wrong, my father couldn't make me cry. He would beat me a lot . . . but I would not cry. Why should I cry? I wasn't wrong."

Lum also says he has discovered in himself what his friends and family had long known--an ugly pattern of resentment and rage.

"When I was 3 or 4 years old, I can remember going to a playground with my older cousin. I tripped over a teeter-totter and fell. I peed in my pants and I blamed my cousin for tripping me. Twenty-five years later at a wedding party, I found something to yell at my cousin about. The party broke up. Can you believe I held something inside me from the time I was a 4-year-old child?"

Although talking to Eist once a week has helped break his pattern of rage and psychosomatic illness, Lum says he "could not function without the medication." In the last five years, Eist has medicated Lum with a half- dozen different antidepressants, ranging from lithium ("it made me high") to Elavil ("which makes my fingers tremble and my mouth dry"). Lum finds the side-effects of Elavil so annoying that he is planning to go back to lithium.

If not for the drugs, Lum says he constantly feels "damned if I do and damned if I don't. The medicine smooths out the highs and the lows. It kinda brings you into the middle."

Without the antidepressants, Eist says Lum would probably need four or five hours a week of psychotherapy to keep from regressing into his "entrenched pathological patterns of coping." Last summer Lum stopped seeing Eist and stopped taking drugs. Within weeks, he was hospitalized for stomach pains.

"I thought I didn't need it last year. I thought, hey, I'm doing pretty good. I was wrong," says Lum. "Now I wouldn't even put a timetable on it. The progress I have made for me and my family is well worth it."