The Centers for Disease Control and Prevention last week came out with an interesting study on postpartum depression (PPD) in 17 states. It was based on a survey of new mothers. Maine had the lowest rate at 11.7 percent. New Mexico, at an astonishing 20.4 percent, had the highest. Minnesota, with 12.7 percent, was at the low end.

PPD is not the same as the baby blues. That’s always struck me as a poetic phrase for such an ironic condition: You’re supposed to be so happy but all you can do is cry. It’s a common and blessedly fleeting condition that affects many new moms. “It’s just hormones,” people say. “It will pass.” But PPD is a far more serious affliction that needs recognition and treatment because it can be harmful to both the mother and the infant.

Not suprisingly, women with the most difficult lives report much higher rates of PPD, according to the CDC: Young mothers, those with the least education, those on Medicaid, women who give birth to low weight infants, and those who report partner abuse and financial stress. White women report the lowest rates compared to women of other races and ethnicities.The CDC says that women with PPD are less likely to engage with their infants or to play with them, and may be less willing to breastfeed.

So your doctor should ask you about your mood and whether you feel depressed at your first visit after delivery.

I wasn’t depressed after giving birth, but I vividly remember the baby blues. I’m glad I knew the difference.

What was your experience?