Behavioral and psychological symptoms in Alzheimer's disease: frequency and relationship with duration and severity of the disease.

The occurrence of behavioral and psychological symptoms of dementia (BPSD) is currently recognized as an important aspect of Alzheimer's disease (AD). We evaluated the frequency and severity of BPSD with the Neuropsychiatric Inventory across the various degrees and phases of the disease in 50 consecutive AD outpatients. Apathy, aberrant motor activity, dysphoria and anxiety were the symptoms most frequently reported by the caregivers, ranging in the whole study sample from 46 to 74%. A clear trend towards increasing frequency with the severity of disease was found for delusions, hallucinations and aberrant motor activity. A major effect of the duration of the disease was found in the probability of developing hallucinations and aberrant motor activity. Apart from hallucinations, all BPSD were present starting from a mild degree of dementia. A better understanding of the global spectrum of BPSD in AD is warranted in order to improve the allocation of health resources toward the treatment of dementia.