Ten percent of new mothers develop postpartum depression a clinical disorder that may occur a few days or even months after childbirth. This condition may prevent a woman from doing the things she needs to do every day. Postpartum depression requires treatment, yet fewer than 50% of women with this disorder seek help.

In postpartum psychosis, the new mother loses contact with reality for periods of time. This is the rarest postpartum disorder, occurring in about one in 1,000 births, but its effects can be tragic. Onset is sudden and usually occurs within the first two to three weeks.

Twomey had a frightening experience during a visit from her mother-in-law. While Twomey was carrying her daughter, Ariana, across the threshold at the top of the stairs, she thought about tossing her down. Rather than tell her mother-in-law about it, Twomey dealt with her disruptive thinking by avoiding the stairs.

"I thought I heard people whispering and laughing," said Twomey. "I was paranoid that my husband was plotting to take my child away and divorce me." Having a crying, colicky child added to the stress. Even when the baby wasn't crying, Twomey would imagine she heard crying.

A woman with mild symptoms may benefit from counseling. More severe symptoms usually indicate a need for medication.

Postpartum psychosis is an emergency and requires immediate medical attention. Although a postpartum depression usually follows, this disorder is treatable and prognosis is good with early intervention.

Teresa Twomey made it through depression and psychosis after the birth of her first child at age 32. But two years later, when pregnant with twins, she was afraid of having the horrible thoughts creep back. "It was very emotional, very hard," she says. Confined to bed rest during her pregnancy, Twomey surfed the Internet and read about postpartum depression. She joined chat groups, where she described her experience and was told she probably had experienced postpartum psychosis.

"I was terrified about being diagnosed as depressed and being told I needed treatment, but I was also afraid of being told I wasn't depressed, because, then what I would do?" After the birth of her twins, she was diagnosed with postpartum depression. Twomey started medications and therapy immediately.

Today, Twomey continues to confront her illness. She's working on a book about women's experiences following childbirth, gathering stories of other mothers who went through postpartum mood disorders. The book will not just be about depression, however. She wants to explore the full range of women's experiences following childbirth. "The idea," says Twomey, "is that any mother can pick up the book and see herself in it."