As many as 1 out of 4 women experience some degree of postpartum depression. During pregnancy, the level of progesterone is extremely high. Progesterone is a hormone that decreases anxiety, reduces insomnia through its natural sedating properties, and has antidepressant effects. After childbirth, there is a steep reduction in the amount of progesterone produced, which some research indicates is the cause of postpartum depression. With the use of antidepressants, or with progesterone alone, many new mothers have an improved quality of life during the postpartum period.