Objective: To investigate the prevalence of and risk factors for behavioral and psychological symptoms in Taiwanese Alzheimer's disease (AD) patients.

Method: Consecutive AD patients from the Memory Clinic of the Taipei Veterans General Hospital were studied. Cognitive function was evaluated using the Chinese version of the Cognitive Abilities Screening Instrument. Primary caregivers were interviewed for the Clinical Dementia Rating scale, the Barthel Index, and the Alzheimer's Deficit Scale. Behavioral and psychological symptoms were assessed using the Behavioral Pathology in Alzheimer's Disease Rating Scale.

Results: Of the 142 participants, 73 (50.7%) had at least one delusion. The most frequent delusion was delusion of theft (N = 43, 30.3%). Thirty-five patients (24.6%) experienced hallucination. Fifty-seven patients (40.1%) had activity disturbances and 39 (27.5%) had aggression. Patients were divided into two subgroups according to the presence or absence of each cluster of symptoms, namely, delusions, hallucinations, activity disturbance, aggression, diurnal rhythm change, affective symptoms, and anxiety. There was no significant correlation between age, age at onset of dementia, number of years of education, and duration of illness and each cluster of symptoms. Correlation between severity of behavioral and psychological symptoms of dementia and cognitive decline was noted.

Conclusions: This study revealed a high prevalence of behavioral and psychological symptoms of dementia in Taiwanese patients with AD and suggests that these symptoms are associated with cognitive deficit.