Prevalence of depression among older Americans: the Aging, Demographics and Memory Study

The Aging, Demographics, and Memory Study (ADAMS) was undertaken in order to determine the national prevalence of dementia and cognitive impairment without dementia in the U.S.A. (Langa +Italic et al -Italic ., 2005; Plassman ., 2007; 2008). A clinical assessment of depression was included in ADAMS, allowing for an estimation of depression prevalence across a variety of population-representative demographic groups. Thus, the present study using the ADAMS sample sought to determine depression prevalence among older adults in the U.S.A., providing information across age strata, sex and various racial and ethnic groups. BACKGROUND: Previous studies have attempted to provide estimates of depression prevalence in older adults. The Aging, Demographics and Memory Study (ADAMS) is a population-representative study that included a depression assessment, providing an opportunity to estimate the prevalence of depression in late life in the U.S.A. METHODS: The ADAMS sample was drawn from the larger Health and Retirement Study. A total of 851 of 856 ADAMS participants aged 71 and older had available depression data. Depression was measured using the Composite International Diagnostic Interview – Short Form (CIDI-SF) and the informant depression section of the Neuropsychiatric Inventory (NPI). We estimated the national prevalence of depression, stratified by age, race, sex, and cognitive status. Logistic regression analyses were performed to examine the association of depression and previously reported risk factors for the condition. RESULTS: When combining symptoms of major or minor depression with reported treatment for depression, we found an overall depression prevalence of 11.19%. Prevalence was similar for men (10.19%) and women (11.44%). Whites and Hispanics had nearly three times the prevalence of depression found in African-Americans. Dementia diagnosis and pain severity were associated with increased depression prevalence, while black race was associated with lower rates of depression. CONCLUSIONS: The finding of similar prevalence estimates for depression in men and women was not consistent with prior research that has shown a female predominance. Given the population-representativeness of our sample, similar depression rates between the sexes in ADAMS may result from racial, ethnic and socioeconomic diversity.