RESUMEN
BACKGROUND: In Alzheimer's disease (AD), cognitive impairment is associated with functional impairment; and neuropsychiatric symptoms are common in AD patients. However, there have been few studies about the relationship between neuropsychiatric symptoms and functional state in AD. The objective of this study is to investigate the effects of neuropsychiatric symptoms on activities of daily living in AD. METHODS: We reviewed the medical records of 60 AD patients meeting the criteria of the Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) for probable AD (mean age, 75.4+/-7.0 years; 13 men, 47 women). The relationships between the Neuropsychiatric Inventory (NPI) and two functional measures, instrumental activities of daily living (IADL) and the Barthel Index, were analysed. RESULTS: The total NPI score was significantly associated with both functional measures (IADL: r=0.543; Barthel Index: r=-0.515), as were the NPI subscale scores of delusion, hallucination, agitation, depression, anxiety, and irritability. Multivariate regression analyses showed that total NPI score and duration of dementia were significant predictive factors for both IADL and the Barthel Index. In addition, the total NPI score still significantly influenced the two functional measures after controlling for age, duration of dementia, and Mini-Mental State Examination. CONCLUSION: The total NPI score was a significant predictive factor for functional status beyond the contribution of cognitive impairment in AD. Neuropsychiatric symptoms are associated with increased functional impairments in AD. Screening and management of neuropsychiatric symptoms during the course of AD would be helpful in improving functional status.