Relationship of behavioral and psychological symptoms to cognitive impairment and functional status in Alzheimer's disease

OBJECTIVE: This cross-sectional study examined the relationship of behavioral and psychological symptoms to cognitive and functional impairment in Alzheimer's disease (AD). DESIGN: One hundred and fourteen patients were evaluated consecutively at a university-affiliated outpatient memory disorders clinic and diagnosed with possible or probable Alzheimer's disease (AD) according to NINCDS-ADRDA criteria. Subjects were assessed with the Behavioral Pathology in Alzheimer's Disease Scale (BEHAVE-AD), Revised Memory and Behavior Problem Checklist (RMBPC), Blessed Dementia Scale (BDS), and Mini-Mental State Examination (MMSE). RESULTS: Several symptoms of behavioral pathology showed associations with MMSE scores, including activity disturbances, delusions, and hallucinations. After controlling for the variance associated with the MMSE, activity disturbances, diurnal disturbances, delusions, and hallucinations were linked with BDS scores. CONCLUSIONS: The results suggest that some non-cognitive symptoms may be related to the neurobiologic mechanisms underlying the increased cognitive dysfunction in AD. Specific symptoms of behavioral pathology may also impact a patient's ability to perform important self-maintenance behaviors.