By Gina Shaw on WebMD

When Tina Merritt gave birth to her son Graham six years ago, she expected what all new mothers expect: a joyous experience getting to know her baby. Instead, she found that she was terrified of her own child.

“I came home and I cried for hours straight. I was afraid that somebody would leave me alone with this baby that I had no clue how to take care of,” she recalls.

Stricken with the fear that she would be an incompetent mother, Merritt went back to work when Graham was 6 weeks old, ceding most of the baby’s care to her husband and the grandparents.

“It wasn’t that I didn’t want to take care of him -- I just thought they were better at it,” she says. “I felt like I couldn’t do it right. My husband knew something was wrong, and he picked up the pieces. He just thought, OK, I need to step up to the plate and be a responsible husband.”

Merritt, who now lives in southern California, wouldn’t learn the truth until her son was more than 2 years old: she was suffering from postpartum depression (PPD). Between 10% and 20% of women who have recently given birth experience PPD, but like Merritt, more than half of them go undiagnosed.