The association between poor dental health and depression: findings from a large-scale, population-based study (the NHANES study)

Objective: To examine the relationship of poor dental health and depression, controlling for markers of inflammation (C-reactive protein; CRP) and adiposity (body mass index; BMI). Method: Data from two National Health and Nutrition Examination Surveys (2005-2008) were utilized (n= 10. 214). Dental health was assessed using the Oral Health Questionnaire (OHQ). Depression was measured using the Patient Health Questionnaire-9 (PHQ-9), where cases were identified using a cut off score of 10 or above. Logistic regression was applied to measure magnitude of associations, controlling for a range of covariates including CRP and BMI. Results: After adjustment for covariates, a significant dose-response relationship between number of oral health conditions and likelihood of PHQ-9 defined depression was observed. Compared with individuals without an oral health condition, adjusted odds ratio (95 confidence interval) for depression in those with two, four and six conditions were 1.60 (1.08-2.38), 2.13 (1.46-3.11) and 3.94 (2.72-5.72), respectively. Level of CRP and being underweight or obese were associated with being depressed. Conclusions: A positive association exists between poor dental health and depression that is independent of CRP and BMI.