Black people are less likely to get major depressive disorder (MDD) than white people, but when they do it tends to be more severe
The researchers estimated the prevalence, persistence, and treatment of depression as well as its disabling characteristics in 3570 African Americans, 1621 Caribbean Blacks, and 891 non-Hispanic White people participating in the National Survey of American Life. All the participants were at least 18 years old.
White patients had the highest lifetime prevalence of MDD, at 17.9%, followed by Caribbean Blacks, at 12.9%, and African Americans, at 10.4%. However, 12-month MDD estimates were similar across the three groups.
Despite having a lower prevalence of MDD, Black patients of both ethnicities were significantly more likely than White patients to have chronic MDD. The ratio of patients with 12-month MDD in the sample of lifetime cases indicated chronic MDD for 56.5% of African Americans and 56.0% of Caribbean Blacks, compared with 38.6% of White patients.
Reporting the findings in the Archives of General Psychiatry, the team stresses the burden of MDD on Black patients.
For example, Black patients with MDD reported being completely unable to work or carry out normal daily activities on an average of 10 days during the previous month, compared with only 3 days for White depressed patients.
More Black than White patients reported severe or very severe impairment in their daily activities, at 74.4% versus 63.6%. While this did not reach statistical significance, significant differences were seen when daily activities were divided into home, work, relationship, and social domains.
Social function appeared to be the domain most affected, with 55.4% of Black patients, compared with 34.2% of White patients, reporting high levels of impairment.
"These data suggest that when Blacks develop MDD, it is likely debilitating in impact and persistent in its course. It is important to find out why Blacks who develop this illness have a poorer prognosis than their White counterparts," say Williams et al.
Prevalence and Distribution of Major Depressive Disorder in African Americans, Caribbean Blacks, and Non-Hispanic Whites