Researchers have found that mothers suffering from postpartum depression who take anti depressants are more likely to have infants with healthy weight gain when compared to babies of mothers who went untreated. The findings suggest women should seek treatment even if they need to take anti-depressants while breast feeding. Postpartum depression in the first six months after giving birth affects 12 percent to 15 percent of new mothers. Symptoms include low self-esteem, feelings of inadequacy, inability to enjoy the baby or usual activities, lack of energy, insomnia, lack of concentration and irritability. Researchers studied 78 breast-feeding mothers who began taking anti-depressants for mood or anxiety disorders either during pregnancy or within four weeks of giving birth. Mothers who are depressed might be less inclined to breast feed their children. Depression also has an effect on biological variables in the mother's milk. The study led investigators to conclude that number of factors could influence the reduced weight gain.