The rates for a major depressive episode are two to three times higher for women than for men in almost all of the countries and cultures which have been studied. Women are also much more likely to develop a full-blown anxiety disorder than men are. Depressed women make more suicide attempts than men, and they report more sleep disturbance, more bodily and health problems, and more severe symptoms. Women with bipolar disorder tend to have more depressions and more rapid cycling episodes than men.
Evidence suggests that some biological aspects of being female make women more prone to depression.
Estrogen treatment can help lift depressed mood in women who are heading into menopause. Likewise, women are more likely to develop thyroid problems than men, and since the thyroid hormone is involved in the regulation of mood and metabolism, this may make them more vulnerable to depressive disorders. Women produce less than half the amount of the brain chemical serotonin that men do, and serotonin is critical to mood and appetite. The overall structure and function of the brain differ between men and women, from before birth and throughout the lifespan. For instance, women process language tasks on both sides of their brains, while men tend to use one side only.