Scientists are examining many potential causes for and contributing factors to women’s increased risk for depression. It is likely that genetic, biological, chemical, hormonal, environmental, psychological, and social factors all intersect to contribute to depression.

Genetics

If a woman has a family history of depression, she may be more at risk of    developing the illness. However, this is not a hard and fast rule.   Depression can occur in women without family histories of depression, and women from families with a history of depression may not develop depression themselves. Genetics research indicates that the risk for developing depression likely involves the combination of multiple genes with environmental or other factors.

Brain chemicals and hormones

Brain chemistry appears to be a significant factor in depressive disorders. Modern brain-imaging technologies, such as magnetic resonance imaging (MRI), have shown that the brains of people suffering from depression look different than those of people without depression. The parts of the brain responsible for regulating mood, thinking, sleep, appetite and behavior don’t appear to be functioning normally. In addition, important neurotransmitters-chemicals that brain cells use to communicate-appear to be out of balance. But these images do not reveal WHY the depression has occurred.

Environmental and biological factors including stress, poor diet, neurotoxins, or genetics cause cause imbalances in the levels of neurotransmitter chemicals in the brain.  These imbalances can trigger or exacerbate depressive symptoms.

Scientists are also studying the influence of female hormones, which change throughout life. Researchers have shown that hormones directly affect the brain chemistry that controls emotions and mood. Specific times during a woman’s life are of particular interest, including puberty; the times before menstrual periods; before, during, and just after pregnancy (postpartum); and just prior to and during menopause (perimenopause).

Premenstrual dysphoric disorder

Some women may be susceptible to a severe form of premenstrual syndrome called premenstrual dysphoric disorder (PMDD). Women affected by PMDD typically experience depression, anxiety, irritability and mood swings the week before menstruation, in such a way that interferes with their normal functioning. Women with debilitating PMDD do not necessarily have unusual hormone changes, but they do have different responses to these changes. They may also have a history of other mood disorders and differences in brain chemistry that cause them to be more sensitive to menstruation-related hormone changes. Scientists are exploring how the cyclical rise and fall of estrogen and other hormones may affect the brain chemistry that is associated with depressive illness.

Postpartum depression

Women are particularly vulnerable to depression after giving birth, when hormonal and physical changes and the new responsibility of caring for a newborn can be overwhelming. Many new mothers experience a brief episode of mild mood changes known as the “baby blues,” but some will suffer from postpartum depression, a much more serious condition that requires active treatment and emotional support for the new mother. One study found that postpartum women are at an increased risk for several mental disorders, including depression, for several months after childbirth.

Some studies suggest that women who experience postpartum depression often have had prior depressive episodes. Some experience it during their pregnancies, but it often goes undetected. Research suggests that visits to the doctor may be good opportunities for screening for depression both during pregnancy and in the postpartum period.

Menopause

Hormonal changes increase during the transition between premenopause to menopause. While some women may transition into menopause without any problems with mood, others experience an increased risk for depression. This seems to occur even among women without a history of depression. However, depression becomes less common for women during the post-menopause period.

Stress

Stressful life events such as trauma, loss of a loved one, a difficult relationship or any stressful situation-whether welcome or unwelcome-often occur before a depressive episode. Additional work and home responsibilities, caring for children and aging parents, abuse, and poverty also may trigger a depressive episode. Evidence suggests that women respond differently than men to these events, making them more prone to depression. In fact, research indicates that women respond in such a way that prolongs their feelings of stress more so than men, increasing the risk for depression. However, it is unclear why some women faced with enormous challenges develop depression, and some with similar challenges do not.