ALL OF US FEEL down sometimes, but some of us get down and can't come up again. Depression is the only clinically recognized psychic illness that is frequently fatal: it ends all too often in suicide. There are from 40 to 65 million depressives in the United States. Two-thirds of them, the consistent large majority of diagnosed cases, are women. Housewives and wage-earners alike -- home-and-babies or office-and-career, it makes no difference. A person taught by her society to perceive herself as a born loser is going to find it to feel like a winner. Maggie Scarf's Unfinished Business is a big book on a big subject: depression in women.

What is depression?

"I keep making decisions and then disassembling them. . . ." That's Brenda, one of the many voices in the book, women interviewed at clincs and hospitals.

"Feeling as if I'm in mouring for something without having any notion what that something is. . . ." That's Diana.

"If one conceives of life as a kind of continuous thread," says Scarf, "Then depression is a place of snarling, of tangling, of stoppage . . . a signal of adaptive failure."

The symptoms include the inability to experience pleasure, impaired ability to think and remember, indecisiveness, irritability, fatigue (or frenzied activity), sleep problems, impotence or frigidity, sadness, lack of interest in anything outside one's self and one's pain. "The mood state itself is a filter of experience, allowing nothing cheerful or gratifying to come through."

These are only indications; Scarf does not "define" depression and then color in the outlines. The whole book is a definition, and the picture she gives of depression grows out of and remains rooted in individual case studies, and in her discussions of theories and therapies. These discussions are of a breadth and equanimity rather unusual in the field. While making her own inclinations clear, Scarf leaves us free to think. No instant certainties are offered. This is a work of popular psychology, written in accessible journalistic prose without technical jargon; it's for Us, not for Them. But it isn't "pop psych." Opinion is not uttered, but presented for examination.

The book is eminently judicious, in that it makes very few judgments. And it is admirably good-natured. It isn't always easy to keep one's cool in the shot-torn area between the Male-as-Norm bastions of traditional psychology and the Male-as-Enemy outposts of radical feminism, but Maggie Scarf never loses her head. She can even cope with Freud's famous statement, "What we shall never know is what a woman really wants." Some women, including this reviewer, automatically foam at the mouth at the fatuousness of the remark, its bland arrogation of cognition to men -- for who, after all, are "we"? Again and again, the male is human; the woman is deviant. But Scarf mildly calls the statement "rather ironical," and goes on: "What I am trying to do is actually turn the question from a semimocking one to a perfectly serious one -- to ask what it is that, when lacking in a woman's life, can lead to states of depression? What do women, at the various stages of their lives, require in order to live?"

Well, cheers for that question -- cheers and praise.

The subtitle, "Pressure Points in the Lives of Women," is misleading if it sounds like another predictable-crises manual. The "stages of their lives" are simply the six decades from the teens to 70, each exemplified by one or several portrait-interviews, each voice, each woman a facet of the dark jewel; Loss, Mourning, Terror, Despair, Anger, Loneliness.

The first great loss in the adolescent's life is that of her childhood. She must trade baby security for adult independence, and if love fails along the way, she may perceive the process not as liberation but as abandonment, and be left to cope with life, not in hope and trust, but in grief and fear. And at each phase of life this pattern may arise or recur. And always the achievement of self-reliance, of a self that can freely be and do in the world, is hampered by the cultural bias that encourages a woman to ask, "What do I want to do, to be?"

For me, the weakeast parts of the book are the sections on women over 50. Scarf is very funny about the doctors who consider old age -- in women, not in men -- as abnormal and as curable; but her agrument against the "hormone replacement thereapy" school seems to lead her into some sweeping denitals. She refuses to connect depression with menopausal hormone changes in any way. Evidence supports her in that depression is not statistically any more frequent in the year 45-55 than before or after. The conventient stereotype of the moody bitchy crazy menopausal woman -- give her Valium, it's all hormones -- is out. But, having connected depresion directly with hormone changes at puberty and after childbirth, I wonder why Scarf dismisses the hormone so absolutely at menopause, not even considering hormone fluctuation (as opposed to loss), nor mentioning the often careless prescription of oral hormones, including the Pill, a possible cause of depressive states. The one case study for the fifties is curiously atypical; after hearing about the woman's childhood you can only admire her for getting to age 52 at all. In the sixties, again only one case study, and again some proselytizing -- for ECT, electroshock. I found the discussion of this hot subject cursory, compared to the full, solid discussings of drugs used to treat of depression. And "Mrs. Garvey" -- all the others are on firstname basis, only this one is distanced -- seems dull, insipid, a typical little old lady, seen with so little empathy that Scarf twice admits to "feeling strange" when asking her about her mother. But are not grandmothers allowed to be daughters? And if ECT is so safe for Mrs. Carvey, nd so helpful, despite the fact that nobody can say what it does, why not use ECT on depressives of 40, or 30, or 15? But Scarf doesn't suggest that; leaving me with an unhappy and probably unjust impression that she thinks ECT is fine for old depressives. But why? Because the old depressives are right, at last? Because what they knew, all along, waking alone in the black pit of 2 a.m., is true -- they don't matter any more?

Scarf has not the sensitive ear of such interviewers as Ronald Blythe; all her informants tend to sound alike, sharing her own rather flat casual style. But this is a minor flaw in a book of real weight integrity. Depression is an immensely complex subject, and the patience and comprehensiveness of Maggie Scarf's handing are perfectly appropriate. Depression might to be depressing subject, but the voices of women from the darkness are very moving, and Unfinished Business is, in its firmness and intelligence and charity, an invigorating, hope-giving book.