Prevalence and correlates of behavioral and psychiatric symptoms in community‐dwelling elders with dementia or mild cognitive impairment: the Memory and Medical Care Study

BACKGROUND: Little is known about the prevalence and correlates of behavioral and psychiatric symptoms of dementia in community-dwelling elders with dementia or mild cognitive impairment (MCI). METHODS: 512 people with Mini-Mental State Examination (MMSE) scores < 24 or a decline of at least 4 points over two administrations, and their knowledgeable informants (KIs) were enrolled in the MMCS. The classification of subjects as having dementia or MCI was based on a neuropsychological battery of four tests, not a clinical diagnostic evaluation. The sample for this study included 454 subjects (dementia n = 333; MCI n = 121) and their KIs. Demographic and health-related characteristics of subjects and KIs were obtained during KI interviews. Multivariate logistic regression was used in statistical analysis. RESULTS: Compared to dementia subjects, those classified as MCI had a lower prevalence (47.1% vs 66.1%) of any symptoms (psychosis, depression, or agitation), and of agitation (24.8% vs 45.1%). Symptoms of psychosis and depression also were less prevalent, even though differences did not reach statistical significance. In the dementia group symptoms were associated with a report of a physician's diagnosis of dementia, greater functional impairment, and a KI who was a child/child-in-law. In those with MCI, symptoms were correlated with being white, greater functional impairment, and a younger, less educated, KI. CONCLUSIONS: Psychiatric and behavioral symptoms were common in community-residing elders with cognitive impairment, but their prevalence and correlates differed by study classification as having dementia or MCI. Identifying and treating these symptoms may benefit patients with cognitive impairment and their families. Longitudinal studies on the predictors, changes in prevalence, and effectiveness of treatments for psychopathology of dementia are needed.