Confounding experts, who expected to find the opposite, a recent study revealed that African-American women who live in rural areas develop major depression and other mood disorders far less frequently than their urban counterparts. These findings were revealed in an article published in the April edition of the peer-reviewed journal JAMA Psychiatry, and seem likely to provoke much discussion and further study as mental health professionals attempt to grasp the implications of this surprising discovery.
A team of researchers, led by Dr. Addie Weaver of the University of Michigan, set out to compare the rates of depression and mood disorders in rural residents with those of people living in cities or well-populated suburbs. They were also interested in studying the racial and ethnic aspects of the problem, specifically the differences in incidence between African-American women and non-Hispanic Caucasian women in general.
Using data obtained in the National Survey of American Life, a 2001-2003 project designed to investigate racial and ethnic disparities in mental health diagnoses and treatment , the researchers identified lifetime and previous 12-month incidence of major depressive illness and mood disorders (bipolar disorder, seasonal affective disorder, etc.) among more than 1,800 women. All the study subjects came from Southern states and were divided into four groups (non-Hispanic Caucasians and African-Americans living in either rural or urban areas) for the purposes of comparative analysis.
Depression and Mood Disorders by Zip Code
Overall, non-Hispanic Caucasian women had a significantly elevated lifetime risk for both major depression (as clinically defined) and mood disorders in comparison to African-American women. The rates of incidence were 21.3 percent versus 10.1 percent for depression and 21.8 percent versus 13.6 percent for mood disorders respectively. The disparity remained for diagnoses of depression made in just the previous 12 months, with 8.8 percent of non-Hispanic Caucasian women and 5.5 percent of African-American women registering positive for contemporary mental illness.
When broken down by geography, among Caucasian women the risks of previous-year depression and/or mood disorders were almost three times greater for those living in rural areas. The numbers revealed a rural-region incidence of 10.3 percent for both categories of mental illness, in contrast to the 3.7 (depression) and 3.8 (mood disorder) percent risks faced by Caucasian women residing in urban settings.
But the situation was reversed for African-American women. For major depression and mood disorders, for both lifetime and previous 12-month occurrence, women residing in rural areas were much better off, as this statistical comparison shows:
- Lifetime incidence of major depression for African-American women, urban versus rural: 10.4 percent to 4.2 percent
- Previous 12-month incidence of major depression for the same group, urban versus rural: 5.3 percent to 1.5 percent
- Lifetime incidence of clinically-recognized mood disorders, urban versus rural: 13.9 percent to 6.7 percent
- Previous 12-month incidence of clinically-recognized mood disorders, urban versus rural: 7.6 percent versus 3.3 percent
In every category, urban African-American women were at least twice as besieged as their rural counterparts, in total contradiction to the numbers obtained from the study of non-Hispanic Caucasian women. And among African-American women who’d undergone bouts of depression recently, the urban/rural ratio of incidence was more than three-and-a-half to one.
It is also interesting to note one other point of divergence between Caucasian women and African-American women. While major depression and mood disorders occur with virtually identical frequency in the former group, among the latter demographic mood disorders are apparently far more common.
Geography and Mental Illness: Mapping New Territory
There are clearly hidden social, economic and cultural factors at work here that explain the rural and urban splits and the diversity between the two racial/ethnic groups. As a general overview, this JAMA Psychiatry article is both surprising and revealing, but a lot more research will be required before its results can be truly comprehended and properly interpreted.
But the discovery that geography is relevant to mental illness is important and will ultimately lead to a better understanding of how conditions like depression develop. Until now, little has been known about depression and mood disorders in African-American women, or in people living in rural areas. Consequently, any studies that increase knowledge about mental illness in these understudied and possibly underdiagnosed groups will be highly useful for mental health professionals tasked with serving these constituencies.