Behavioral and psychological symptoms assessed with the BEHAVE-AD-FW are differentially associated with cognitive dysfunction in Alzheimer's disease.

To assess the possible neurological basis of behavioral and psychological symptoms of dementia (BPSD), the relationships between BPSD and cognitive function were evaluated in 40 patients with Alzheimer's disease (AD). BPSD was assessed using the Behavioral Pathology in Alzheimer's Disease Frequency Weighted Severity Scale (BEHAVE-AD-FW) for behavioral symptoms and psychological symptoms separately, and cognitive function was also assessed using the Cognitive Abilities Screening Instrument (CASI). We found that only behavioral symptoms were associated with cognitive function based on the CASI total score and the score for the CASI attention domain. Administration of risperidone, an atypical anti-psychotic drug, for one month, improved the behavioral symptoms and the scores for the CASI attention and orientation domains. Our data suggest that BPSD in AD may reflect two largely independent pathophysiological processes: one associated with behavioral symptoms partly overlapping with attention, and the other associated with psychological symptoms predominantly unrelated to cognitive function.