For reasons researchers are still trying to understand, clinical depression appears to be almost twice as common in women as in men. Statistics show that approximately 24% of women suffer a major depressive episode at some point in their lives, compared with 15% of men (Hirschfeld et al., 1997).
According to a consensus panel sponsored by the National Depressive and Manic Depressive Association (NDMDA), whose results appeared in the Jan. 22/29, 1997 issue of JAMA, depression is one of the most prevalent of all medical illnesses in both men and women. It is associated with long duration of episodes, high rates of chronicity, relapse and recurrence, psychosocial and physical impairment, and mortality and morbidity, with a 15% risk of death from suicide in patients who have ever been hospitalized for depression.
Despite these facts, the panel noted that the vast majority of patients with chronic depression are misdiagnosed, receive inappropriate or inadequate treatment, or are given no treatment at all.
Why females are more prone to this debilitating disease than their male counterparts is still under investigation, although significant progress has been made.
Depression is a common and costly mental illness that affects approximately 17.6 million Americans each year (National Institute of Mental Health D/ART Online Information, 1998). Yet of all people who are depressed, only 10% will get the treatment they need (Robins and Regier, 1991).
According to a 1996 National Mental Health Association (NMHA) survey, only one out of three women who experience clinical depression will ever seek care, and women experience increased depression between the ages of 25 and 44 (Weissman, 1984).
Research data indicate that people suffering from depression have imbalances in the activity of the neurotransmitters in the brain. Two neurotransmitters implicated in depression are serotonin and norepinephrine. Scientists believe a deficiency in serotonin may cause the sleep problems, irritability and anxiety associated with depression. They also believe a decreased amount of norepinephrine, which regulates alertness and arousal, may contribute to the fatigue and depressed mood of the illness (American Psychiatric Association Online Public Information, 1997).
In 1997, investigators at McGill University used new imaging techniques to measure serotonin secreted in the brains of eight healthy men and seven healthy women. The results of the study showed that as a group, the men produced 52% more of the neurotransmitter than did the women. These findings, which appeared in the May 13, 1997 issue of the Proceedings of the National Academy of Sciences, indicate a causal link between depression and serotonin activity (Nishizawa et al., 1997).
To date, there is insufficient evidence to indicate that natural menopause causes depression (Nichol-Smith, 1995). Among postmenopausal women who suffer depression, psychosocial factors appear to be the main predictors of depression. These include a past history of depression, socioeconomic status, stressful life events such as the death of a loved one, and negative beliefs about menopause. Various studies have found no direct correlation between estrogen levels and depression.
There is also inconclusive evidence that hormone replacement therapy improves depression in women who seek help for menopausal problems (Hunter, 1996). Such therapy is used to alleviate hot flashes, night sweats and other vasomotor symptoms that accompany menopause in some women.
American Psychiatric Association Online Public Information (1997), Depression. Available at http://www.psych.org. Accessed May 29, 1998.
Hirschfeld RMA, Keller MB, Panico S et al. (1997), The National Depressive and Manic-Depressive Association consensus statement on the undertreatment of depression. JAMA 277:333-340.
Hunter M (1996), Depression and the menopause (editorial). Br Med J 313:1217-1218.
Kendler KS, Walters EE, Truett KR et al. (1994), Sources of individual differences in depressive symptoms: analysis of two samples of twins and their families. Am J Psychiatry 51:1605-1614.
National Institute of Mental Health D/ART Online Public Information (1998), Depression Awareness, Recognition and Treatment. Available at http://www.nimh.nih.gov/dart/darthome.htm. Accessed June 4, 1998.
National Institute of Mental Health (1994): Depressive Illness: Treatments Bring New Hope. NIH Publication No. 94-3612.
National Institute of Mental Health (1995), Depression: What Every Woman Should Know. NIH Publication No. 95-3871.
Nishizawa S, Benkelfat C, Young SN et al. (1997), Differences between males and females in rates of serotonin synthesis in human brain. Proc Natl Acad Sci U S A 94(10):5308-5313.
Robins LN, Regier DA, eds. (1991), Psychiatric Disorders in America: The Epidemiologic Catchment Area Study. New York, NY: Free Press. As cited in Hirschfield et al. NDMA Consensus Statement, p. 334.
Weissman M (1984), Onset of major depression in early adulthood. Increased familial loading and specificity. Arch Gen Psychiatry 41(12):1136-1143.