Prevalence estimates of depression in elderly community-dwelling African Americans in Indianapolis and Yoruba in Ibadan, Nigeria

Background: This is a community-based longitudinal epidemiological comparative study of elderly African Americans in Indianapolis and elderly Yoruba in Ibadan, Nigeria. Method: A two-stage study was designed in which community-based individuals were first screened using the Community Screening Interview for Dementia. The second stage was a full clinical assessment, which included use of the Geriatric Depression Scale, of a smaller sub-sample of individuals selected on the basis of their performance in the screening interview. Prevalence of depression was estimated using sampling weights according to the sampling stratification scheme for clinical assessment. Results: Some 2627 individuals were evaluated at the first stage in Indianapolis and 2806 in Ibadan. All were aged 69 years and over. Of these, 451 (17.2%) underwent clinical assessment in Indianapolis, while 605 (21.6%) were assessed in Ibadan. The prevalence estimates of both mild and severe depression were similar for the two sites (p = 0.1273 and p = 0.7093): 12.3% (mild depression) and 2.2% (severe depression) in Indianapolis and 19.8% and 1.6% respectively in Ibadan. Some differences were identified in association with demographic characteristics; for example, Ibadan men had a significantly higher prevalence of mild depression than Indianapolis men (p < 0.0001). Poor cognitive performance was associated with significantly higher rates of depression in Yoruba (p = 0.0039). Conclusion: Prevalence of depression was similar for elderly African Americans and Yoruba despite considerable socioeconomic and cultural differences between these populations.