Cognitive impairment and depression among Chinese nonagenarians/centenarians

In this study, we explored the association between cognitive impairment and depression in the very elderly using a sample aged 90-108 years.

A cross-sectional study.

The sample included 682 unrelated Chinese nonagenarians/centenarians (67.25% women, mean age of 93.49 years). The mean depression score (measured with the brief 23-item Geriatrics Depression Scale-Chinese Edition was 8.45 (standard deviation [SD] = 3.30). The mean of cognitive function scores (measured with the 30-item Mini-Mental State Examination) was 15.54 (SD = 5.38). There was no significant difference in cognitive function scores between subjects with and without depression, and there was also no significant difference in depression scores between subjects with and without cognitive impairment. There was also no significant difference in the frequency of depression between subjects with and without cognitive impairment or in the frequency of cognitive impairment between subjects with and without depression. Both the odds ratio (OR) of depression (as a function of increased cognitive impairment) and the OR of cognitive impairment (as a function of increased depression) were found to be insignificant. Pearson Correlation also showed no significant correlation between depression scores and cognitive function scores.

In summary, we found that depression was not directly correlated with cognitive impairment in Chinese nonagenarians and centenarians.