Neuropsychiatric symptoms are associated with increased risks of progression to dementia: a 2-year prospective study of 321 Chinese older persons with mild cognitive impairment.

ABSTRACT

BACKGROUND: studies have suggested that neuropsychiatric (NP) symptoms influence the development of dementia among older adults. But, the results are inconsistent and there is limited information about NP symptoms in population-based samples. OBJECTIVE: to explore the association between NP symptoms and risk of cognitive decline in Chinese older persons residing in the community. DESIGN: prospective study. SETTING: community sample. SUBJECTS: a total of 321 community-dwelling Chinese older persons aged 60 or over with mild cognitive impairment participated in the study. METHODS: at baseline, each subject was assessed with Clinical Dementia Rating (CDR), Mini-Mental State Examination, list learning and delayed recall, and Category Verbal Fluency Test. Severity of NP symptoms was evaluated with Neuropsychiatric Inventory (NPI). Global cognitive status at the end of 2-year study period was determined by CDR. RESULTS: at baseline, 40.5% of participants exhibited one or more NP symptoms (NPI total score ≥ 1). Night-time behaviours (22.1%), depression (16.8%), apathy (14.0%) and anxiety (12.8%) were the most common NP symptoms. At the end of 2-year follow-up, 27.5% of participants with depression at baseline developed dementia, compared with 14.8% of those without depression (χ² = 4.90, P= 0.03). Aberrant motor behaviour was also significantly associated with deterioration in cognition (χ² = 5.84, P= 0.02), although it was an infrequent occurrence. On logistic regression analysis, only depression at baseline was shown to be a risk factor for progression to dementia (OR= 2.40, 95% CI 1.05-5.46, P= 0.04). CONCLUSION: depression in non-demented older persons may represent an independent dimension reflecting early neuronal degeneration. Further studies should be conducted to assess whether effective management of NP symptoms exerts beneficial effects on cognitive function.