Characteristics of Neuropsychiatric Inventory Questionnaire Domain Scores Related to Cognitive Function in Alzheimer's Disease Dementia.

Introduction: Alzheimer's disease dementia (ADD) is a common cognitive disease in Japan. Mild cognitive impairment (MCI) is regarded as an early, but abnormal state of cognitive impairment, and amnestic MCI (aMCI) as a precursor of ADD. The Revised Hasegawa Dementia Scale (HDS-R) and the similar Mini-Mental State Examination (MMSE) are quick cognitive assessments widely used in Japan. Behavioral and psychological symptoms of dementia (BPSD) are commonly assessed using the Neuropsychiatric Inventory Questionnaire (NPI-Q). However, when the different types of BPSD appear and how they progress with the progression of ADD is not clear. Methods: A total of 553 outpatients with ADD or aMCI participated. We divided the patients into six cognitive function groups. We examined the relationship between the individual NPI-Q domain scores and cognitive function to reveal the appearance and progression of BPSD. We also examined the relationship of the NPI-Q domains with the HDS-R and MMSE domains to reveal the cognitive functions that affect the BPSD. Results: Our results suggested that hallucinations, agitation/aggression, anxiety, irritability/lability appeared in association with high MMSE scores and progressed slowly. Apathy/indifference and aberrant motor behaviors appeared in association with middle MMSE scores and progressed slowly. Delusions and nighttime behavior disturbances appeared in association with high MMSE score and progressed consistently with the ADD. Memory and orientation were the cognitive functions most related to NPI-Q domain scores and thus to progression of BPSD. Conclusions: Memory and orientation may be the most important cognitive functions related to the progression of BPSD in patients with ADD. [ABSTRACT FROM AUTHOR]