The interrelations between psychosis, behavioral disturbance, and depression in Alzheimer disease

Behavioral changes are common in Alzheimer disease (AD), and heterogeneous in their presentation. Subtle personality changes tend to occur early; these include apathy, irritability and inability to pay attention. Later agitation, aggression and disinhibited behaviors may appear. We have utilized the Columbia University Scale for Psychopathology in Alzheimer's Disease to monitor a number of behavioral symptoms in 235 patients with early probable AD. Markov analyses were used to predict the probability of developing or retaining a given symptom at 6-month follow-up. The results show that the symptoms of psychopathology in AD fluctuate with time. Agitation was both the most frequent and persistent symptom, while paranoid delusions and hallucinations were less persistent. Most behavioral disturbances, except paranoid delusions, were associated with greater cognitive impairment. There was no association between depressive features and either cognitive or functional impairment. These results have important implications for the optimal treatment of the psychopathological symptoms of AD.