Gary Goldsmith went through a decade and more of hell with manic-depression before he discovered lithium.

He had his first episode of mania in college, when he suddenly found himself possessed by wild, grandiose ideas and boundless yet futile energy. He had his first crippling bout of depression a few years later, when he worked as a buyer for Macy's.The depression recurred, predictably-every September, when pre-Christmas job pressures hit their peak. "I lost my ability to work and my grasp of basic things," Goldsmith said. "I'd just sit there and do nothing all day."

Antidepressant drug treatment snapped him out of that, but then the mania came back. Now Goldsmith takes lithium regularly-"I'll probably take it for the rest of my life"-and is doing fine.

Florence Gassman leads a near-normal life because her recurrent depression is kept under control by antidepressant drugs, which are believed to right a chemical imbalance in the brain. She enrolled in a program for elderly depressed persons at New York University Medical Center two years ago and has had only one relapse since then.

Nancy Scheff says electroconvulsive therapy in which powerful electric shocks are administered to the brain, saved her life. She had been prescribed "every drug in the book" for recurrent bouts of depression and hadn't been doing that well. "The best I've ever been is in the hospital after ECT," she said.

Three patients, each with a different kind of depressive disorder, with one thing in common: There's a treatment to help each one.

That's true of almost all depressive patients.

"Depression is a medical illness that is now highly treatable, says Dr. Robert M. Post of the National Institute of Mental Health.

The problem now is getting that treatment to the people who need it, something that doesn't happen often enough.

"The data show that only about a third of severly depressed patients get any sort of treatment," says Dr. Donald Klein of the New York Psychiatric Institute. "What most of them get is inadequate."

Patients don't recognize the condition. Doctors often miss the diagnosis, treating the symptoms patients complain about-insomnia and headaches, for example-rather than the underlying causes. Society puts a stigma not only on mental illness but also on visiting a psychiatrist.

Any alert doctor can diagnose depression, Klein says, but it takes time-time spent talking to the patient. The doctor has to recognize the symptoms of depression and rule out possible psysical causes such as thyroid deficiency.

"The three major signs are interest, energy and pleasure," Klein says. "If patients have lost interest in everything, have no energy and feel no pleasure, the odds that they are depressed are very high."

Klein is a leading proponent of drug therapy. His new book, "Do You Have a Depressive Illness?" written with Dr. Paul Wender, says, "Medication should be the primary treatment of depressive illness. Psychotherapy often serves only to maintain the patient's morale until medication can work."

They point to well-established statistics showing that better than 80 percent of patients with depression get better with drug treatment. Colleagues don't argue with the effectiveness of antidepressant drugs, especially for severe depression, but say there's a large role for psychotherapy, too.

But the essential message is that almost everyone can be helped.

There's a basis consensus about drug therapy for depression, Post says: "We've got a series of very highly effective treatments, just as for heart arrythmias or hypertension. If one doesn't work, another will."

Treatment for depression usually starts with a tricyclic antidepressant drug (so called because of its molecular structure), Post said.

If the patient doesn't improve in four to six weeks, a different tricyclic can be tried. If that doesn't work, the next step is use of a monoamine oxidase (MAO) inhibitor, a different kind of antidepressant drug that gets its name from its effect on a specific brain chemical.

For the minority of patients who aren't helped, the next step would be to add thyroid hormone or lithium to the antidepressant drug. That is effective in about half of all cases, said Post. For those who still don't respond, the doctor can try a variety of drugs, including anticonvulsants, which normally are prescribed for epilepsy.

For minic-depression, lithium is the mainstay, but anticonvulsants also can help, Post says.

Ideally, he says, drug treatment should be accompanied by psychotherapy, weekly sessions at which the therapist helps the patient deal with the symptoms and stresses of the disease.

Somewhere toward the end of the road is ECT, which can help many of those patients for whom all else fails.

Scheff remembers her ECT treatments as providing some of her more endurable times in her long experience with depression.

"The only unpleasant thing is having the IV (intravenous tube) put into your arm," she said. "I would go to sleep, wake up and it would be all over. ECT did a lot of good for me."

But she noticed a memory loss after her last series of ECT treatments.

"Up to the last four treatments, I didn't lose any memory except the day of the treatment," she said. "Then I lost a lot-first everything, then a big block came back. It's scary, but no more scary than the illness itself."

Gassman says she was helped by ECT but wouldn't have it again because of the memory loss.

"Never, never, never," she said. "It was a horror. I visited by son at summer camp and couldn't remember a thing about it. I couldn't even drive around the neighborhood because I couldn't remember the streets."

Even ECT proponents acknowledge they don't know how it works. But they point out there's the same uncertainty about antidepressant drugs and other treatments for depression.

There's a consensus that the drugs and ECT produce their effects by altering brain chemistry, but the exact mode of action isn't known. It's in brain biochemistry that most psychistrists now look for explanations of mental illness, and where they think there's real hope for ultimate answers.

*Current evidence that psychotherapy can help depressed patients comes from a government-sponsored study, which began in 1977, in which 250 patients with mild to moderate depression were divided into four groups.

One got an antidepressant drug. Two got psychotherapy-either cognitive therapy, which aims at changing the patient's perception of events, or interpersonal therapy which focuses on personal relationships. There was also a placebo group, which got no treatment at all.

The drug worked faster, with patients showing improvement after four weeks. Psychotherapy-both kinds-was slower, with improvement after four to eight weeks. After 16 weeks, all three treatments did about the same. All were better than placebo.

Psychiatrists are still trying to understand the message of the study, said Dr. Gerald Klerman of the Payne Whitney Psychiatric Clinic.

"The problem is that everyone improved in the first 16 weeks, Klerman said. "It's not that the treatments don't work but that all the treatments work. Even 70 percent of the placebo patients got better."

*Electroconvulsive therapy (ECT)-a series of powerful shocks administered to the brain through electrodes placed on the skull- is a last resort treatment for deep depression and other major mental disorders.

Psychiatrists differ about when ECT should be tried. Critics say it shouldn't be used at all.

Dr. Max Fink of the State University of New York at Stony Brook, a leading proponent, believes ECT should be given to "all patients whose condition is severe enough to require hospitalization."

There's some debate about that. But there is agreement among most psychiatrists that ECT works.

A vocal group of critics won't accept that verdict. One of their most prominent spokesmen is Dr. Peter Breggin, a Washington psychiatrist who maintains that ECT produces its effects by causing permanent brain damage.

"There's no doubt you can't be depressed when you have acute organic brain syndrome," Breggin said. "ECT produces an acute organic syndrome. It causes apathy or euphoria, and they call that improvement."

But Breggin runs into a lot of skepticism about that and some of his other views-most notably that depression and other mental illnesses don't have biochemical causes but are simply psychological problems.

The prevailing view is that ECT is a reasonable treatment for the worst cases of depression.

"We did a study here of the most severly affected patients, ECT versus drugs," said Dr. John Mann of the Payne Whitney Psychiatric Clinic. "With ECT, patients were out of the hospital two weeks faster."

Mann, like Fink and others who have used ECT, acknowledge that some patients and their families are repulsed by the treatment.

They attribute that rection to a false impression given by such movies as "One Flew Over the Cuckoo's Nest," where ECT is depicted as a weapon to subdue a recalcitrant patient played by Jack Nicholson.

ECT has changed a lot since it was developed in the 1930s Mann says. Then, a patient could be seen literally in convulsions caused by ECT's effect on the brain. Now, sedatives and muscle relaxants eliminate such effects.

Patients can suffer memory loss after ECT, "but it's hard to disentangle it from the effects of the disease," said Harold Sackheim of the New Ypork Psychiatric Institute. He was on a panel assembled by the National Institutes of Health in 1985 to reach a consensus on ECT.

The panel's report called ECT "the most controversial treatment in psychiatry" and noted its "significant side effects" but concluded it is "demonstrably effective for a narrow range of severe psychiatric disorders in a limited number of diagnostic categories."