OBJECTIVE: The purpose of this study was to determine the frequency and
type of psychotic symptoms in patients with probable Alzheimer's disease
and to test whether there is a relationship between specific psychotic
symptoms and episodes of physical aggression. METHOD: From 209 patients
with possible or probable Alzheimer's disease who had been assessed in a
research clinic every 6 months for up to 4.5 years, 181 subjects with
probable Alzheimer's disease were selected for study. On the basis of the
summary note for each visit in the patients' charts, the presence of
delusions, hallucinations, misidentifications, and episodes of physical
aggression was determined. Data regarding psychotic symptoms and aggression
were available for 170 and 169 subjects, respectively. RESULTS: Delusions
had been reported for 74 (43.5%) of the patients and were the most frequent
psychotic symptom; persecutory delusions were the most common type.
Physical aggression had been noted for 50 (29.6%) of the patients.
Delusions and misidentifications frequently preceded and were significantly
associated with episodes of physical aggression. The presence of delusions
was a significant predictor of physical aggression but accounted for only
3.5% of the variance. CONCLUSIONS: This study suggests that delusions are a
risk factor for physical aggression in patients with probable Alzheimer's
disease who have moderate to severe cognitive impairment. As delusions
accounted for only a small percentage of the variance, further research is
needed to identify other variables that may be significant predictors of
physical aggression in this population.