Association Between Smell, Taste, and Depression in Nationally Representative Sample of Older Adults in the United States

Objectives To characterize the association between quantitative olfactory dysfunction (OD) and gustatory dysfunction and depression in older adults. Methods The 2013–2014 National Health and Nutrition Examination Survey (NHANES) data were used to investigate the relationship between smell and taste dysfunction and depression. Adults aged 65 years and older were included in the analysis. For smell status, subjects were divided into hyposmia, anosmia, and OD (hyposmia + anosmia) using the Pocket Smell Test. For taste status, subjects were evaluated using quinine, 1M NaCl, and 0.32M NaCl solutions. Indicator variables were made for subjects with both smell and taste dysfunction to determine whether a combination of symptoms could predict depression. Depression status was evaluated by the 9-item Patient Health Questionnaire using accepted cutoff values. Relevant demographic, socioeconomic, and comorbid factors were included in multivariate logistic regression models, which accounted for the complex survey design of NHANES. Results A total of 931 subjects aged 65 years or older were included in the weighted analysis. Anosmia significantly predicted depressive symptoms in multivariate analysis (odds ratio [OR] = 2.484, P = .032) but not univariate. In univariate analysis, hyposmia + anosmia (OR = 2.193, P = .006) and hyposmia (OR = 2.512, P < .001) significantly predicted depression. Significance was lost in multivariate analysis. Conclusions Smell dysfunction is an independent predictor of depressive symptoms in a representative sample of older adults in the United States after adjusting for relevant demographic factors and comorbidities.