PMS-related moodiness. Post-partum depression. Menopausal melancholy. At each stage of life, women are vulnerable to low spirits. But research shows it's not just the psychological stress of aging, childbirth, or cramps that brings on the blues. It's the physiological factor that ties them together—hormones.
Normal hormonal changes that take place before menstruation and menopause and after childbirth trigger alterations in brain chemistry, fostering depression, says Margaret Spinelli, M.D., director of the Maternal Mental Health Program at the New York State Psychiatric Institute. While people have long linked depression and hormones, now there is hard evidence to support the link.
Hormones released by the ovaries—estrogen and progesterone—actually seem to influence the neurotransmitters, such as serotonin, norepinephrine, and dopamine, that are known to affect mood. Normally, estrogen blocks enzymes that break serotonin down, allowing more of the spirit-lifting substance to stay operative in the brain and act like an antidepressant. But before menstruation, after giving birth, and during menopause, when estrogen levels dip, serotonin levels plunge, too. Studies show that women who suffer from PMS have decreased serotonin levels during that time, and that post-partum depression is likely associated with the fall of estrogen levels and its effect on the brain.