Everyone occasionally feels blue or sad, but these feelings usually pass in a few days. When a woman has a depressive disorder, however, it interferes with daily life and her ability to function normally, causing pain for both her and the people who care about her.

Although depression affects both men and women, more women than men are likely to be diagnosed with depression in any given year. Efforts to explain this difference are ongoing, as researchers explore certain factors, such as possible biological and social factors, unique to women.

Many women with a depressive illness never seek treatment. But the vast majority--even those women with the most severe depression--can get better with treatment.
 

Different Forms of Depression

Depressive disorders that occur in both women and men take different forms. The most common types are major depressive disorder and dysthymic disorder. Minor depression is also common.

Major depressive disorder, also called major depression, is characterized by a combination of symptoms that interfere with a person's ability to work, sleep, study, eat and enjoy once-pleasurable activities. Major depression is disabling and prevents a person from functioning normally. An episode of major depression may occur only once in a person's lifetime, but more often it recurs throughout a person's life.

Dysthymic disorder, also called dysthymia, is characterized by long-term depressive symptoms, often lasting two years or longer; however, these symptoms are less severe than the symptoms of major depression. Dysthymia may not disable a person, but it prevents one from functioning normally or feeling well.

People with dysthymia may also experience one or more episodes of major depression during their lifetimes.

Minor depression may also occur. Symptoms of minor depression are similar to major depression and dysthymia, but they're less severe or don't last as long. That said, minor depression is not a condition any person should ignore.

Some forms of depressive disorder have slightly different characteristics than the three common types; sometimes these other types develop under unique circumstances. However, not all scientists agree on how to characterize and define these forms of depression.

Psychotic depression occurs when a severe depressive illness is accompanied by some form of psychosis, such as a break with reality, experiencing hallucinations or having delusions.

Seasonal affective disorder (SAD) is characterized by a depressive illness during the winter months, when there is less natural sunlight. The depression generally lifts during spring and summer. SAD may be effectively treated with light therapy, but nearly half of those people diagnosed with SAD don't respond to light therapy alone. Antidepressant medication and psychotherapy also can reduce SAD symptoms, either alone or in combination with light therapy.

Bipolar disorder, also called manic-depressive illness, is not as common as major depression or dysthymia. Bipolar disorder is characterized by cycling mood changes that take a person suffering from the disorder from extreme highs (mania) to extreme lows (depression).

Depression's Signs and Symptoms

Just as all women are different, women with depressive illnesses don't all experience the same symptoms. Not only do depression symptoms vary, their severity, frequency and duration vary depending on the individual and her particular illness.

Common signs and symptoms of depression include the following:

• Persistent sad, anxious or "empty" feelings
• Feelings of hopelessness or pessimism
• Irritability, restlessness, anxiety
• Feelings of guilt, worthlessness or helplessness
• Loss of interest in activities or hobbies once pleasurable, including sex
• Fatigue and decreased energy
• Difficulty concentrating, remembering details and making decisions
• Insomnia, waking up during the night or excessive sleeping
• Overeating or appetite loss
• Thoughts of suicide, suicide attempts
• Persistent aches or pains, headaches, cramps or digestive problems that don't ease with treatment

The Causes of Depression

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

Genetics can come into the equation if a woman has a family history of depression, which then increases her risk of developing the illness. However, this is not a hard and fast rule. Depression can occur in women without family histories of the disorder, 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.

Chemicals and hormones in the brain and body appear to be a significant factor in depressive disorders. Modern brain-imaging technologies, such as magnetic resonance imaging (MRI), have shown the brains of people suffering from depression look different than the brains 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. Additionally, important neurotransmitters, the chemicals brain cells use to communicate, appear to be out of balance. But these images don't reveal why the depression has occurred.

Scientists are also studying the influence of female hormones, which change throughout life. Researchers have shown 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):