PROJECT SUMMARY/ABSTRACT
Older adults (85 and older), the fastest growing segment of the population, are at very high risk of dementia.
Some minority groups, such as African Americans, are at higher risk of dementia compared to Whites.
However, little is known about the risk factors that might be involved in their high susceptibility to dementia.
Depression, one of the most frequent and debilitating psychiatric conditions in older adults, has been
consistently associated with cognitive decline in Whites. Although depression in African Americans is more
chronic and untreated, compared with Whites, only a handful of studies have investigated the relationship
between depression and cognitive decline in this racial/ethnic group. To our knowledge, this relationship has
not been examined in oldest-old (≥80) African Americans. Chronic inflammation is also associated with both
depression and cognitive decline. Because depression and inflammation are treatable conditions, better
understanding of their role in cognition may lead to reduced dementia risk in this very high risk, growing, and
understudied population.
This study will examine the inter-relationships of depression and inflammation with change in cognition over
time in 192 non-demented community-dwelling oldest-old African Americans. We will examine the following
three Specific Aims: Aim 1: To examine the association between depression measures and cognitive decline
over time. We hypothesize that: a) Depression is related to a greater rate of cognitive decline. b) Based on
compelling preliminary data, apathy is the depression measure hypothesized to be most strongly related to a
greater rate of cognitive decline. Aim 2: To examine the association between baseline inflammation and
cognitive decline. We hypothesize that higher levels of inflammatory cytokines at baseline are related to a
greater rate of cognitive decline. Aim 3: To examine the inter-relationships of depression, inflammation and
cognitive decline. a) We hypothesize that inflammation serves as a moderator in the relationship between
depression and cognitive decline in oldest-old African Americans. If significant results are generated, they can
lead to increasing public awareness about the importance of timely depression diagnosis and development of
mechanism-based effective and well-targeted treatment for the oldest-old community of African Americans,
who are at particularly high-risk for dementia.