DARKNESS VISIBLE A Memoir of Madness By William Styron Random House. 85 pp. $15.95

IN THE summer of 1985, William Styron gave up alcohol. He tells us that he had abused it for 40 years, but quite suddenly became intolerant of it. It is still not sufficiently widely recognized that, in susceptible people, withdrawal from alcohol may precipitate a depressive illness; but it certainly did so in Styron's case. Typically, he suffered severely from insomnia; untypically, he was better in the morning and at first grew worse as the day went on. The tranquilizer he took to make him sleep probably made his condition worse.

Even so gifted a writer as Styron finds severe depression almost indescribable. Everyone can glibly say, "Of course I know what it is to be depressed," thinking perhaps of a predictable reaction to bereavement or failure. Those who have been there know differently. No one has put it better than Gerard Manley Hopkins.

O the mind, mind has mountains; cliffs of fall

Frightful, sheer, no-man-fathomed. Hold them cheap

May who ne'er hung there.

Styron himself knew the writer Romain Gary and his wife Jean Seberg, both of whom committed suicide; but, in spite of his deep sympathy with their states of depression, the illness seemed remote until he himself experienced it. "The pain of severe depression is quite unimaginable to those who have not suffered it, and it kills in many instances because its anguish can no longer be borne." Styron is rightly impatient with those who regard suicide as weakness. He is also right to object to current psychiatric terminology. "Depression" is an insipid noun which conveys nothing of the horror of the illness.

Giving up alcohol may have precipitated Styron's descent into hell, but what else made him vulnerable? As in all such cases, many factors were involved. He tells us that his father was once hospitalized for depression and fought the illness for most of his life. Genetic studies have shown that, when one parent is affected with manic-depressive illness, 27 percent of the children will suffer from some form of the illness. When both parents are affected, over half the children will become ill. Morever, a depressed parent is not able to give children the care and affection which they need. Genetic liability is compounded by environmental deficit.

Another factor was the death of Styron's mother when he was 13 years old. A number of studies have shown that those who have suffered early bereavement remain more vulnerable to subsequent losses, and are more likely to react to any loss or failure as if it were an irreversible disaster. This is especially so when mourning has been incomplete, as appears to have been the case with William Styron, who might well echo Hamlet's complaint, "How all occasions do inform against me."

Styron was at first treated with anti-depressant drugs combined with psychotherapy. He found his psychiatrist to be platitudinous, and the drugs both intolerably slow to act and also productive of nasty side-effects. For six months his condition progressively worsened. He became seriously concerned that it would end fatally and, one December evening, excused himself from his guests and disposed of a highly personal notebook as a first step toward disposing of himself. Chilled, alone, and utterly miserable, he forced himself to watch the tape of a movie which, fortunately for him, was concerned with music. Brahms's Alto Rhapsody suddenly broke through the icy barrier, pierced his heart, and made him realize that he could not inflict the injury of suicide on those he loved. Next day, he was admitted to a hospital. ALTHOUGH he describes hospitalization as purgatory, he nevertheless believes that it was his salvation. Removal from home also removed him from anxiety and from responsibility. It is hardly surprising that so intelligent and sophisticated a patient found group therapy intensely irritating and art therapy no more than "organized infantilism." "For me," he writes, "the real healers were seclusion and time."

Looking back over his writing, Styron found that suicide had been a more persistent theme than he had realized, and that his descriptions of depression in his characters anticipated his own suffering with revealing accuracy. This is a beautifully written, deeply moving, courageously honest account of an illness which is eminently treatable, but which often goes unrecognized. Styron has made a striking addition to the rather few notable personal accounts of mental illness. But, although he lists some of the many writers and other artists who have killed themselves, he does not explore the relationship between creativity and recurrent depression as fully as one would like him to do.

In my view, vulnerability to depression often acts a spur to creativity, and creative achievement may help to ward off depression. Will he please give us an autobiography in which he tells us more about how his gifts, his insights, and his temperament interacted to make him into a novelist?

Anthony Storr's most recent books are "Solitude," "Churchill's Black Dog, Kafka's Mice and Other Phenomena of the Human Mind" and "Freud."