Depression in bipolar disorder versus major depressive disorder: results from the National Epidemiologic Survey on Alcohol and Related Conditions

Moreno C, Hasin DS, Arango C, Oquendo MA, Vieta E, Liu S, Grant BF, Blanco C. Depression in bipolar disorder versus major depressive disorder: results from the National Epidemiologic Survey on Alcohol and Related Conditions. Bipolar Disord 2012: 14: 271–282. © 2012 The Authors. Journal compilation © 2012 John Wiley & Sons A/S. Objectives: To compare the clinical features and course of major depressive episodes (MDEs) occurring in subjects with bipolar I disorder (BD‐I), bipolar II disorder (BD‐II), and major depressive disorder (MDD). Methods: Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (2001–2002), a nationally representative face‐to‐face survey of more than 43000 adults in the USA, including 5695 subjects with lifetime MDD, 935 with BD‐I and lifetime MDE, and 494 with BD‐II and lifetime MDE. Differences on sociodemographic characteristics and clinical features, course, and treatment patterns of MDE were analyzed. Results: Most depressive symptoms, family psychiatric history, anxiety disorders, alcohol and drug use disorders, and personality disorders were more frequent—and number of depressive symptoms per MDE was higher—among subjects with BD‐I, followed by BD‐II, and MDD. BD‐I individuals experienced a higher number of lifetime MDEs, had a poorer quality of life, and received significantly more treatment for MDE than BD‐II and MDD subjects. Individuals with BD‐I and BD‐II experienced their first mood episode about ten years earlier than those with MDD (21.2, 20.5, and 30.4 years, respectively). Conclusions: Our results support the existence of a spectrum of severity of MDE, with highest severity for BD‐I, followed by BD‐II and MDD, suggesting the utility of dimensional assessments in current categorical classifications.