Prevalence of mood disorders in a national sample of young American adults

Background. Availability of nationally representative mood disorder prevalence estimates in the United States, based on structured psychiatric interviews is limited. This report estimates overall lifetime prevalence of major depressive episode, dysthymia, and bipolar disorder using the Third National Health and Nutrition Examination Survey (NHANES III) and compares these estimates to the Epidemiologic Catchment Area Study (ECA) conducted 10 years earlier. Additionally, prevalence estimate breakdowns by selected socio-demographic and health characteristics are investigated. Methods. NHANES III, conducted from 1988 to 1994, is a large nationally representative cross-sectional sample of the United States. A population-based sample of 8,602 men and women 17-39 years of age were eligible to participate, of whom 7,667 (89.1%) completed interviews. Mood disorder assessments came from the Diagnostic Interview Schedule (DIS) administered as one component of the NHANES III. Results. Lifetime prevalence estimates were assessed for six mood measures: 1) major depressive episode (MDE) 8.6%, 2) major depressive episode with severity (MDE-s) 7.7%, 3) dysthymia 6.2%, 4) MDE-s with dysthymia 3.4%, 5) any bipolar disorder 1.6%, and 6) any mood disorder 11.5%. All estimates except for MDE and MDE-s were significantly higher than comparable ECA estimates. Conclusions. These data provide recent national prevalence estimates. Based on their overall magnitudes, subgroup excesses, and observed increases compared to the ECA, continued monitoring of these estimates is warranted.