This study will evaluate the effectiveness of taking supplemental calcium while pregnant in reducing the risk of postpartum depression.

Postpartum depression is a combination of physical, emotional, and behavioral changes that occur after childbirth. The rapid drop in estrogen and progesterone levels, as well as the social and psychological changes resulting from the birth of a child, can often trigger depression in women. Common symptoms include crying, irritability, fatigue, loss of appetite, and feelings of guilt and anxiety. Women who develop postpartum depression often feel unable to care for their baby or themselves. Postpartum depression is common; it is estimated that about 10 percent of new mothers experience some symptoms of depression following delivery. Risk factors include a personal or family history of depression and a history of suffering from premenstrual dysphoric disorder (PMDD), a severe form of premenstrual syndrome (PMS). The purpose of this study is to evaluate the effectiveness of calcium supplements taken during pregnancy in reducing the likelihood of postpartum depression in women at risk for developing this condition.

Pregnant women who are at risk for developing postpartum depression will be enrolled in this study when they are between 16 to 26 weeks pregnant. All recruited women will undergo psychological testing for screening purposes. Women who are found to be depressed or suffering from other psychiatric disorders during screening will be referred to alternative treatment and will not be enrolled in this study. All participants will then be randomly assigned to receive either a calcium supplement (2 grams) or placebo on a daily basis. Treatments will continue throughout the remainder of each woman's pregnancy and for 12 weeks after she gives birth. Outcome measurements will include standardized questionnaires and psychiatric interviews to assess depression levels. If any participant exhibits significant depressive symptoms, she will be referred for psychiatric treatment. All measurements will be assessed at Weeks 26, 32 and 38 of the pregnancy, and 6 and 12 weeks after giving birth.

Inclusion Criteria:

• Less than 26 weeks pregnant
• At risk for postpartum depression due to a family or personal history of depression or history of premenstrual dysphoric disorder (PMDD)

Exclusion Criteria:

• Currently depressed
• Currently taking medications for depression, bipolar disorder, or schizophrenia
• History of medication treatment for depression within 3 months of study entry
• Any of the following illnesses: diabetes, kidney disease, parathyroid disease, or untreated thyroid disease
• Currently taking a diuretic or calcium channel blocker
• Does not speak English