OBJECTIVES: Depression is a major public health concern with significant patient and societal burden. However, many patients with depressive symptoms do not receive treatment. This study examined nationally representative estimates of the prevalence of depressive symptoms and factors associated with treatment. METHODS: A cross-sectional, retrospective analysis of adults age ≥18 represented in the 2005-2010 National Health and Nutrition Examination Survey (NHANES) data (n=15,838; weighted n=194,685,449) who responded to the Patient Health Questionnaire (PHQ-9) was conducted. Depressive symptoms were defined by PHQ-9 score≥5. Depression treatment was defined as receiving either antidepressants or psychotherapy. Multivariate logistic regression analyses using population weights were performed to identify factors associated with having depressive symptoms. Among the group of patients with moderate to severe depression, similar models assessed factors associated with receipt of treatment.  RESULTS: The prevalence of depressive symptoms increased gradually from 2005-2010 (21.4% in 2005-2006; 25.6% in 2007-2008; and 26.1% in 2009-2010). Among patients with moderate to severe depressive symptoms, over one-third (weighted n= 6,132,302; 37.0 %) received either antidepressants or psychotherapy treatment. Multivariate results found that comorbidities (high blood pressure, diabetes, asthma, arthritis, heart failure, stroke, COPD, and obesity), previous hospitalization, having no health insurance, seeing a mental professional, receiving antipsychotic drugs, female, Hispanic ethnicity, in poverty status, and age of 20-59 (vs. age<20) were significant factors associated with having depressive symptoms (P<0.05). Among patients with moderate to severe depression, comorbidities (asthma and cancer), seeing a mental professional, receiving antipsychotic drugs, female, and Non-Hispanic White race were statistically significantly associated with receipt of treatment (P<0.05). CONCLUSIONS: Although the prevalence of depression symptoms is high and growing in the U.S. population, only a small portion of patients with moderate to severe depression received treatments. Additionally, significant disparities by ethnicity and use of mental professionals appear to be associated with the likelihood of receiving treatment.