BOOK REVIEW / NONFICTION : Balancing the Highs and the Lows : AN UNQUIET MIND <i> by Kay Redfield Jamison</i> ; Alfred A. Knopf $22, 224 pages

A hundred years ago, the mentally ill were still locked in asylums and the mind was uncharted territory. Since then, psychoanalysis, psychological testing and neuroscientific discoveries about the structure and chemistry of the brain have dissolved the miasma of shame that once surrounded mental illness.

As the 20th century draws to a close, we are hearing from the afflicted what the world is like to the mentally ill.

What they have to tell us is fascinating in itself, but it also offers a guide to those who discover, because of revolutionary new genetic detection techniques, that they are likely to suffer from a mental illness.

In “An Unquiet Mind,” Kay Redfield Jamison recounts her experiences with manic-depressive disease, and by the example of her successful life demonstrates that it is possible to live well in spite of, and perhaps also because of, its burden.

Jamison is at once a manic-depressive and one of the nation’s leading authorities on the condition. A professor of psychiatry at the Johns Hopkins Medical School, she has written the standard textbooks on the subject.

Those were written from the outside. This memoir, written from the inside, recounts the life she knew on the roller coaster of disease, rushing madly around the parking lot at 2 a.m. in her manic phase, buying extravagantly and wallowing in an intense sensual sea only to plunge with accelerating speed into the depths of suicidal despair.

Jamison is able to describe these adventures because she is among the lucky majority of depressives who respond positively to lithium--a neuropharmaceutical drug. This medication has allowed Jamison to rise professionally and build a happy marriage.

Jamison’s story is a paean both to drug therapy and to the devotion of those who cared enough to help her when she could not help herself. The miracle drug--lithium--to which she credits her survival was not enough by itself. She discovered that lithium could dispel her depression long before she was convinced that she was really ill and needed it to survive.

Like many others with her condition, Jamison rejected the medication until, desperate to avoid the suicidal pit of depression, she admitted to herself that the high of the manic phase was tied to the down cycle and that the price of denial could be death.

In “An Unquiet Mind,” Jamison describes her family and suggests the condition is hereditary. She recounts how her illness notwithstanding, she was able by dint of intelligence and personal charm to succeed professionally, travel well, dine well and, above all, love well.

This is not a novel, and Redfield is not especially adept at portraying other people. Her lovers share a sameness--exquisite sensitivity, love of poetry, music--and all seem to have been especially nurturing and sensitive to her plight.

Somehow each is there when she needs him, and Jamison gracefully acknowledges that lithium aside, she owes her life to those who have loved her.

This cannot be a prescription for others, of course. Luck in love takes more than the whirl of a souped-up brain. But this is not a textbook and the only message she has for those who share her condition is to accept medication.

Having come to terms intellectually with her condition, Jamison finally sees visual proof that it is physiologically real.

Sitting in a medical lecture, she watches projected MRI images of the inside of the brain of a manic-depressive. She describes how “a depressed brain will show up in cold, brain- inactive deep blues, dark purples, and hunter greens; the same brain when hypomanic, however, is lit up like a Christmas tree, with vivid patches of bright reds and yellows and oranges.

Never has the color and structure of science so completely captured the cold inward deadness of depression or the vibrant, active engagement of mania.”

Acknowledging her dependence on lithium, Jamison recalls wistfully the joys she once knew during manic phases. But because lithium works for her, she concludes that if she had the choice of not having manic-depressive disease, she would choose to have it:

“As a result of it,” she writes, “I have felt more things, more deeply; had more experiences, more intensely; loved more, and been more loved; laughed more often for having cried more often; appreciated more the springs, for all the winters.”

Jamison is wise not to generalize beyond her own experience and her own disease. There are some conditions for which there is no cheerful upside or a successful chemical cure.

But manic-depression as she knows it can be a gift, she suggests, if properly monitored. In essence, she is arguing for diversity, for a society in which those whose brains differ chemically from the norm can be accepted, appreciated and loved.