"I have had agoraphobia for six years," wrote the woman, "and for the first two I just thought I was dying. A psychiatrist told my husband I was doing it to control him, and it broke up a 20-year marriage. . ."

From a man: "I have been hounded by this malady for years to the point that I was hospitalized. Doctors thought it was my heart or thyroid or blood sugar . . . I just get scared half to death when all these weird panic symptoms gang up on me . . . but it makes me feel better to know that I'm not the only poor fool who has to ride on this bumpy road."

Sometimes they cower in their houses for years, terrified, unable to drive, to shop, to walk to the corner. They are plagued with recurrent terrors--and then the anxiety that the terror will come again. They hide. They live their lives in the aching loneliness that they are somehow uniquely cursed.

In fact, according to the National Institute of Mental Health, there are at least a million people at any given time who suffer "panic attacks," who are called "agoraphobics" when diagnosed correctly.

But because hiding is in itself part of the syndrome, NIMH adds that the "figure is probably low . . . after all, not so many go for treatment and hiding makes it difficult to count . . ."

Even now, agoraphobics are dismissed as eccentric (or worse), mentally ill or even manipulative or manipulated. It appears that most of the victims are women, leading some to explain the syndrome as a political phenomenon linked to sex discrimination. Indeed, for those susceptible to panic attacks and the often attendant phobias that build up around them, almost anything--from having a tooth pulled to a death in the family--can set off the syndrome for the first time.

Or it can come seemingly from nowhere. First there is a shaky, shivery pang, a feeling of strangeness followed usually by what doctors call "noodle legs," along with pounding heart and speeding pulse, sweaty palms and sometimes waves of nausea. Then terror building on terror, a feeling of choking, of being suffocated, a need to get away from wherever you are when it hits.

In many victims, for reasons no more clear to professionals than the cause of the initial panic attack, phobias build up--sometimes about places where panic attacks have occurred and sometimes "in places that make people feel anxious," says Dr. Robert Dupont, director of the Phobia Program of Washington.

Part of this pattern, he speculates, is because of the close relationship of anxiety and excitement. "Take the modern shopping mall. It has been designed to be an exciting place to shop. There are dangling escalators, glass elevators--it's designed for excitement. But excitement and anxiety are so closely related that these shopping centers are phobic torture."

So the victims develop what the specialists call "anticipatory anxiety," which can be so strong that the victim will avoid any place that might precipitate an attack.

This, says Dupont, helps explain why about 60 percent of those who seek help at his center "have a problem with driving. It is the single most common symptom. That is because of the uncontrolled nature of the driving experience and the potential danger. If you're worried you're going to lose control of yourself, where are you most anxious? Behind the wheel of a car."

Also, he has found, "phobic people have this incredible sensitivity to being embarrassed in public, making fools of themselves. By and large they worry a lot about that and one of their major concerns is that they're going to get into some kind of public place and embarrass themselves or others."

Then, says Dupont, "the world shrinks. You can't go shopping, you can't give a talk, take a walk, fly anywhere . . . you can't, you can't, you can't . . ." Finally, over this conglomeration of fear, phobia and anxiety there comes a shroud of depression. "Who wouldn't be depressed?" asks Dupont. "It would almost be abnormal not to be."

It has only been about five years since the cluster of symptoms now known as "panic disorder" came to be seen by researchers and therapists as a genuine medical entity.

But specialists have been much longer coming to any agreement over its nature and treatment. On the one hand was a varied army of psychotherapists holding that it was a purely psychological disturbance and advocating approaches ranging from fullscale psychoanalysis to cognitive-behavioral desensitization or relaxation techniques.

On the other hand: A smaller group of psychopharmacologists whose research suggested that in many cases complex biochemical processes were at work. These specialists, led by Dr. Donald F. Klein of the New York State Psychiatric Institute and Dr. David Sheehan of the Massachusetts General Hospital in Boston, among others, found that their panic-disordered patients benefited significantly from certain classes of drugs--so-called MAO inhibitors and some tricyclic anti-depressants.

They also found the most benefit came from combining drugs that blocked the panic with some form of psychotherapy addressing the anxiety and the phobias.

By this time, however, psychoactive drugs, says Klein, were getting a bad name. Many of the panic victims had "overused sedatives, tranquilizers and alcohol," and their behaviorally oriented therapists saw the drugs as "at best, splints, and at worst, treacherous, because they got in the way of confronting and managing anxiety."

Advocates of this no-medicine approach--Dr. Arthur Hardy in California and Dr. Dupont here, for example--eschewed the use of most drugs and promoted gradual desensitization as the answer. (Dupont calls his approach "supported exposure.")

"But then," says Klein, "they began to see some of their own patients, those they were unable to help, suddenly doing very well on certain drugs . . ."

Moreover, during this period, the entire psychotherapeutic community was made privy to the current breakthroughs in brain research, to the discovery of the brain's messenger chemicals--neurotransmitters--along with striking new evidence about the interaction of beliefs, perceptions of external events and biochemistry.

And even though, "like everything, an approach becomes vested," as Klein puts it, there has recently been an extraordinary meeting of minds among those treating the panic-disordered.

Dupont, a psychiatrist and former head of the National Institute on Drug Abuse, now announces he has "put my white coat back on."

At a meeting on phobia treatments earlier this month in White Plains, N.Y., attended by leaders of both persuasions, a virtual peace treaty was signed in an atmosphere some have described as a "love feast."

Advocates of medication assured colleagues "It's always best to try without drugs first." Behaviorists, as Dupont paraphrases, declared, "Of course there are people who need drugs and anybody who denies them medication is not really devoted to the welfare of the patients, but committed first to their own ideology."

Part of the occasion for this unusual rapprochement is the start of a worldwide trial of a drug that seems to have had some initial success in blocking panic attacks in some selected subjects.

The drug, alprazolam, trade-named Xanax by Upjohn, the manufacturer, has been on the market for some time as an anti-anxiety medication. In certain (large) doses it now appears to control the panic as well as the anticipatory anxiety. In a relatively unusual move, the drug company has applied to the FDA for approval for a new use and is sponsoring the new clinical trials.

Xanax seems to have fewer serious side effects than medications used earlier and there is some reason to believe, says Dupont, that it may also have an antidepressant effect. "But what has been interesting," he says, "is that whether one uses medication or a behavioral approach, the depression lifts when the phobia lifts."

Dupont now feels that a distinction must be made between people who have "panic disorder and a large percentage of phobics who do not." Those with "simple phobias where distress is completely limited to a specific exposure to an elevator, say, or an airplane are probably not benefited by medications being used for panic disorders."

Those who might benefit, however, are people who:

* Suffer spontaneous panic attacks unrelated to phobic situations, including most so-called agoraphobics.

* Do not benefit from cognitive-behavioral programs (up to 20 or 25 percent).

* Improve with non-drug approaches so far as their phobias are concerned, but continue to suffer a level of distress because of the panic attacks.

The main thing to emphasize, Dupont now believes, is that "this disorder be seen as a medical problem and that patients with the problem have access to medical care."

For general information on panic disorders and location of clinical trials on Xanax, write Phobia Society of America, 6191 Executive Blvd., Rockville 20852.