Descent into darkness _ postpartum depression.

Byline: Louise Kiernan

CHICAGO _ The mothers are searching for their daughters.

They are always searching for their daughters, even though their daughters have been dead for more than a year now.

At a march on the lakefront, the two women share a hug and a murmured joke, heads close, hands woven together. On the telephone, they whisper so they won't wake napping grandchildren.

In a meeting of mental health experts at a dingy medical library, they trade a quick wave across the room. They explain who they are.

"I'm Carol Blocker and I lost my daughter through postpartum psychosis."

"I'm Joan Mudd and I lost my daughter to postpartum depression four weeks after Carol's daughter, Melanie, took her life."

Carol Blocker reaches for a discarded napkin to wipe her eyes. Joan Mudd pushes past the crack in her voice.

The two mothers aren't friends so much as allies. They want the same answers. They want to know why their daughters, after giving birth to the children they desperately wanted and desperately wanted to love, became mentally ill and took their own lives. They want to make sure that no one else's daughter dies.

In obvious ways, they are different. Carol is black, petite and precise, with hands that reach out unconsciously to smooth wrinkles and brush away crumbs. Joan is white, tall and blond, with a raucous laugh and the frame of the model she once was. But they are also alike, in their anger and determination and the pain in their eyes sharp as hooks.

Even their apartments are similar, airy, high-rise perches cluttered with evidence they have gathered in their struggle to understand: videotapes, pamphlets, articles from medical journals. A worn handout on how to deal with someone who is depressed, a laminated eulogy, a plastic bag with 12 bottles of pills and, everywhere, photographs.

Look at Jennifer Mudd Houghtaling in her wedding dress, her gloved arms flung wide in joy. Look at Melanie Stokes, her pregnant belly bursting bare from beneath a red scarf wrapped around her chest.

Look at Melanie at 20, a homecoming queen waving from a car, flowers tucked into the crook of her arm. Look at Jennifer at 12, sitting on a raft in a lake, a sheet of dark hair hanging to her…