Postpartum or postnatal depression is a complex mix of physical, emotional, and behavioral changes that occur in a mother after giving birth. Depression may occur in women at during the pregnancy or after the delivery of the child.

Postpartum depression occurs after delivery because of the hormonal changes in a woman's body. About 70-80% of woman experience this, and it may appear within days of delivery or within a year.

During pregnancy, the levels of two female hormones, estrogen and progesterone, rise greatly. In the first 24 hours after childbirth, these rapidly drop back to their normal non-pregnant levels. Researchers think that this fast change in hormone levels may trigger depression, just as smaller changes in hormones can affect a woman's moods before the menstrual cycle. Also, drops in the levels of thyroid hormones which helps to regulate metabolism is responsible for prompting depression.

The amount of blood in the body, the blood pressure, the immune system and metabolism all change after giving birth. These changes affect how one feels physically and emotionally, causing fatigue or mood swings. There is no exact cause known for depression after childbirth, but it's likely that physical, emotional and lifestyle factors all play a role.

Often, the depression is not recognized or treated, because some normal pregnancy changes cause similar symptoms and are happening at the same time. Tiredness, problems sleeping, stronger emotional reactions, and changes in body weight occur during and after pregnancy. But these symptoms may also be signs of depression.

The major causes include a family history of depression or substance abuse, little support from family and friends, anxiety about the fetus, problems with a previous pregnancy or birth, marital or financial problems, young age of mother, feeling tiredness after delivery, broken sleep patterns, feeling less attractive, and doubting one's ability to be a good mother.

Sometimes, women think they have to be the perfect "super mom," which can add stress. Having to stay home or indoors for longer periods of time and having less time to spend with one?s husband or partner and loved ones also results in depression.

There is a difference between baby blues and postpartum depression. Baby blues can happen in the days right after childbirth and normally go away within a few days to a week, whereas postpartum depression can happen anytime within the first year after childbirth and needs to be treated by a doctor.

Talk therapies and anti-depressant medicines are the best ways to overcome and avoid this depression. Taking a nap when the baby does, asking for help from family members and friends, and talking with other moms definitely helps. Keeping a diary to note down emotions and feelings also works as a vent.