Anywhere from 5-25% of women who give birth get some form of post-natal depression. One reason for the wide range in the numbers is the difficulty of pinning down exactly what it is. But women who have had it know too well what it feels like.
Anywhere from a few days to a few weeks after giving birth, some women will feel 'the blues', a moodiness that seems unrelated to external events. It may last only a few days, or as long as a couple of weeks. Longer depressions may be a sign of something more fundamental. Here again, one difficulty in discussing the condition is the widely varying time period that women experience.
Symptoms vary, too. Spontaneous crying may be more common and a general malaise may linger. Women may experience an inability to take pleasure in otherwise enjoyable activities. The new mother may have trouble sleeping and feel fatigued during the day.
Women suffering from post-natal depression commonly become obsessively worried about the health of the baby, an exaggerated reaction to a normal concern. She may have a loss of appetite or impaired concentration. Wide mood swings are a normal part of the condition - feeling elated one minute and extremely sad the next. A sense of worthlessness is not uncommon.
In some extreme cases, she may have suicidal thoughts. In severe cases, women have considered killing their infants in order not to leave them helpless after her suicide. Sometimes these go beyond the normal postpartum depression into a condition called postpartum psychosis. Having a thought, no matter how troublesome, is no cause for alarm. Taking steps to act on it may indicate a more serious problem.
The causes are not known with certainty, but they're almost certainly (at least in part) the result of rapidly changing hormones. Both estrogen and progesterone increase considerably during pregnancy, then drop rapidly back to non-pregnant levels within 24 hours after birth.
But, that is also a reason to be optimistic. When hormones change rapidly, the body has a remarkable ability to bring things back into equilibrium. Expectant mothers can take comfort in knowing that the condition is (usually) short-lived and that it rarely interferes with her ability to care for her baby.
The condition has been widely studied and there are a number of approaches to treatment. Some new mothers benefit from mild anti-depressants for a short while to get them over the period when the symptoms are most severe. Talk therapy is often helpful. Being with not only a professional, but hearing the stories of women who have gone through similar experiences often helps.
Knowing that the condition is normal, short-lived and treatable gives women reason to persist through a difficult time. It's important that women not feel embarrassed to report her symptoms to a spouse or even a professional. Seeking help is the first step to recovery.