Influences of olfactory impairment on depression, cognitive performance, and quality of life in Korean elderly

Despite high prevalence of olfactory loss in the elderly, this is typically overlooked. The aim of this study was to examine the impact of olfactory loss on depression, cognitive performance, and quality of life (QoL) in the general population of South Korea, and also to investigate the association between the above variables. A total of 127 Korean elderly aged from 65 to 89 years participated in this study. Olfactory sensitivity, depression, cognitive performance, and QoL were assessed with T&T olfactometry, the Geriatric Depression Scale, Mini-Mental State Examination, and a questionnaire for Geriatric Quality of Life, respectively. Subjects with severely impaired olfactory function showed a significantly higher degree of depression, lower cognitive performance, and decreased QoL compared to subjects with normal to moderately impaired olfaction. However, when controlling for cognitive performance, the olfactory sensitivity was not correlated with degrees of depression and QoL. In conclusion, our findings confirm the relationships of olfactory loss with depression, cognitive performance, and QoL; they also indicate that tests of olfactory function could be used in the screening for cognitive impairment.