Mental and behavioral disturbances in dementia: Findings from the Cache County Study on Memory in Aging

Objective: The authors report findings from a study of 5,092 community resi dents who constituted 90% of the elderly resident population of Cache Count y, Utah. Method: The 5,092 participants, who were 65 years old or older, were screen ed for dementia. Based on the results of this screen, 1,002 participants (3 29 with dementia and 673 without dementia) underwent comprehensive neuropsy chiatric examinations and were rated on the Neuropsychiatric Inventory, a w idely used method for ascertainment and classification of dementia-associat ed mental and behavioral disturbances. Results: Of the 329 participants with dementia, 214 (65%) had Alzheimer's d isease, 62 (19%) had vascular dementia, and 53 (16%) had another DSM-IV dem entia diagnosis; 201 (61%) had exhibited one or more mental or behavioral d isturbances in the past month. Apathy (27%), depression (24%), and agitatio n/aggression (24%) were the most common in participants with dementia. Thes e disturbances were almost four times more common in participants with deme ntia than in those without. Only modest differences were observed in the pr evalence of mental or behavioral disturbances in different types of dementi a or at different stages of illness: participants with Alzheimer's disease were more likely to have delusions and less likely to have depression. Agit ation/ aggression and aberrant motor behavior were more common in participa nts with advanced dementia. Conclusions: On the basis of their findings in this large community populat ion of elderly people, the authors conclude that a wide range of dementia-a ssociated mental and behavioral disturbances afflict the majority of indivi duals with dementia. Because of their frequency and their adverse effects o n patients and their caregivers, these disturbances should be ascertained a nd treated in all cases of dementia.