The crisis begins for the reader as abruptly as it did for the author: "On July 5, 1996, my daughter was struck mad."

So opens "Hurry Down Sunshine," Michael Greenberg's thought-provoking memoir of his daughter's first episode of full-blown bipolar mania. Sally was 15 when her psychosis sprang up, seemingly overnight. Greenberg, a freelance writer, recalls the night he returned to his Manhattan apartment to discover that his bright, sensitive daughter has been brought home by police who found her "out on the street acting crazy." The girl is babbling incoherently and has acquired a demeanor that her father doesn't recognize.

"It is as if the real Sally has been kidnapped, and here in her place is a demon, like Solomon's, who has appropriated her body," Greenberg writes. "The ancient superstition of possession! How else to come to grips with this grotesque transformation?"

The book follows the next two months as they unfold. Greenberg takes Sally to a psych ward, where he and his family hold vigil, waiting for Sally's heavy medications to bring improvement. There are bewildering talks with doctors and nurses, visits from worried relatives, financial problems, including lack of health insurance. He passes the time watching other patients and their relatives, observing the varied ways families respond to a loved one's insanity. Occasionally he takes time away to help out a brother who is also mentally ill, and whose vulnerability and bleak life seem a chilling, if unstated, potential harbinger of his daughter's future.

There are moments in which family relationships are strengthened, and others in which they're frayed by stress. Greenberg and his wife, Pat, Sally's empathetic stepmother, get into a fight so explosive that Pat locks herself in the bathroom and he tears through the door a la Jack Nicholson in "The Shining."

At one point, wanting to understand how Sally sees the world in her current state, he swallows a dose of her anti-psychotic medication and finds himself hardly able to move, read or think. "I make an effort to care about the simplest things ... but an ungraspable panic comes over me, a panic of indifference, if such a thing is possible, as if I have been relegated to a bit part in the drama of my own existence and, moreover, have missed my cue to step onstage."

Greenberg writes with an emotional clarity that combines compassion for his daughter with a stark, almost pessimistic honesty. He declines to lighten his grim tale with pat conclusions or silver linings. The book offers a somber reminder not to take our own minds, or those of our loved ones, for granted.

Katy Read is a Minneapolis freelance writer who has written for Salon and Brain, Child.