Association of neuropsychiatric symptoms and sub-syndromes with cognitive impairment in community-dwelling Asian elderly.

Abstract

To investigate the presence of neuropsychiatric symptoms (NPS) and sub-syndromes in elderly community-dwelling Asians with varying severity of cognitive impairment. Chinese and Malay participants (n = 613) from the Epidemiology of Dementia in Singapore (EDIS) Study aged ≥ 60 years underwent clinical examination, neuropsychological testing, and NPS assessment using the Neuropsychiatric Inventory (NPI). Diagnosis of no cognitive impairment (NCI), cognitive impairment-no dementia (CIND), including CIND-mild and CIND-moderate, and dementia were made using established criteria. A significant increase in the numbers of NPS was observed accompanying with increasing severity of cognitive impairment (p < 0.001). Compared to those with NCI/CIND-mild, participants with CIND-moderate [Odds ratio (OR): 4.2, 95% confidence interval (CI): 1.8-10.0] or dementia [OR: 9.2, 95% CI: 2.3-36.0] were more likely to have two or more neuropsychiatric sub-syndromes. Participants with CIND-moderate were more likely to have hyperactivity [OR: 2.0, 95% CI: 1.0-3.8] and apathy [OR: 2.9, 95% CI: 1.0-8.4] sub-syndromes, whereas patients with dementia were more likely to have psychosis [OR: 6.9, 95% CI: 2.4-20.1], affective (OR: 8.7, 95% CI: 1.8-42.9), and hyperactivity (OR: 5.4, 95% CI: 1.8-16.1). Furthermore, executive dysfunction and visual memory impairment were associated with the presence of three neuropsychiatric sub-syndromes; whist language and visuomotor speed impairment were related to the presence of two sub-syndromes. By contrast, impairment in attention, verbal memory, and visuoconstruction were not associated with any of the sub-syndromes. The presence of NPS and sub-syndromes increase with increasing severities of cognitive impairment, and different neuropsychiatric syndromes are associated with specific impairment on cognitive domains in community-dwelling Asian elderly.