Psychopathological features in Alzheimer's disease: Course and relationship with cognitive status

OBJECTIVES: To examine the course, clinical correlates, and relationship between cognitive status and psychopathological features in patients with probable Alzheimer's disease (AD) followed over a 5-year period. DESIGN: Cohort study with follow-up of 5 years. SETTING: Patients were recruited at three sites: 91 patients at Columbia Medical Center, 84 at Johns Hopkins School of Medicine, and 61 at Massachusetts General Hospital. PARTICIPANTS: Patients diagnosed with probable AD (n = 236) enrolled in a longitudinal study (Predictors study). MEASUREMENTS: Wandering/agitation, physical aggression, hallucinations, and delusions were evaluated at 6-month intervals using the Columbia Scale for Psychopathology in Alzheimer's Disease. Descriptive analyses were used to provide estimates of prevalence and course of psychopathological features. General estimating equations determined the odds of having any of the four psychopathological behaviors as a function of cognitive status. Markov analyses provided 6-month transition probabilities for psychopathological behaviors given patients' cognitive status and the presence or absence of such behaviors in the previous evaluation. RESULTS: For wandering/agitation, prevalence (39-57%) and persistence increased as a function of time and decrement in cognitive status. Physical aggression was less prevalent (6-22%) and increased as a function of cognitive decline but tended to persist only in the more severely impaired patients. Delusions (34-49%) reached a peak at the second year and then declined. The odds of delusions were maximal with intermediate decline but remained persistent regardless of cognitive status. Hallucinations, despite some fluctuations, were relatively stable during the follow-up period (8-17%) and moderately persistent. CONCLUSION: Psychopathological features, particularly wandering/agitation and delusions, in AD were common throughout the disease course. The natural history and persistence of the four psychopathological features varied. These findings provide important information to clinicians and caregivers regarding the course, predictability, and possible treatment of psychopathological behaviors in patients with probable AD.