The risk of temporomandibular disorder in patients with depression: A population-based cohort study

Objectives: This study used a population-based retrospective cohort design to examine whether depression is a risk factor of temporomandibular disorder (TMD) Methods: From a universal insurance database, we identified 7587 patients who are newly diagnosed individuals with depression in 2000 and 2001. A total of 30 197 comparison subjects were randomly selected from a nondepression cohort. Both groups were followed until the end of 2008 to measure the incidence of TMD. Results: The incidence of TMD was 2.65 times higher in the depression cohort than in the nondepression cohort (6.16 versus 2.32 per 1000 person-years). The hazard ratio (HR) measured by multivariate Cox's proportional hazard regression analysis of TMD for the depression cohort was 2.21 (95% confidence interval (CI) 1.83-2.66), after controlling for socio-demographic factors and other psychiatric comorbidities. Women had higher risk to develop TMD than men (HR 1.61, 95% CI 1.36-1.92 for women without depression; HR 3.54, 95% CI 2.81-4.45 for women with depression). Conclusions: This study demonstrates that patients with depression are at an elevated risk of developing TMD.