Comorbidity of Late-Life Depression in the United States: A Population-based Study Aude Manetti, M.D., Nicolas Hoertel, M.D., M.P.H., Yann Le Strat, M.D., Ph.D., Jean-Pierre Schuster, M.D., C edric Lemogne, M.D., Ph.D., Fr ed eric Limosin, M.D., Ph.D. Objectives: This study sought to determine the clinical and sociodemographic correlates and the treatment-seeking rate of major depressive disorder (MDD), diag- nosed according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, among older adults and its association with comorbid psychiatric disorders and perceived health status. Methods: Data were drawn from the 2001e2002 National Epidemiologic Survey on Alcohol and Related Conditions, a large cross- sectional survey (N ¼ 43,093) representative of the US population. Results: Compared with participants aged 65 years and older without a 12-month diagnosis of MDD, those with MDD were more likely to have lifetime and 12-month comorbid psychiatric disorders. Except for lifetime dysthymia, we found no significant inter- action between rates of current somatic comorbidity, lifetime and 12-month psychi- atric comorbidity, and age groups. Compared with younger participants with a 12-month MDD, they had an older age at onset, reported a similar number of lifetime major depressive episodes and perceived health status, and had lower mental health service utilization rates. Conclusions: Current major depression in the elderly seems to be as disabling as in younger adults in terms of comorbid psychiatric disorders and impaired quality of life. Poorer prognosis of MDD in older adults might be explained by a lower perceived need of treatment, resulting in a lower rate of treatment-seeking behavior. (Am J Geriatr Psychiatry 2014; 22:1292e1306) Key Words: Comorbidity, depression, epidemiology, National Epidemiologic Survey on Alcohol and Related Conditions I n the context of population aging, major depres- sive disorder (MDD) in the elderly represents an increasing public health issue. 1e3 In the United States, it has been estimated that the number of older adults with mental illness will increase from 4 million in 1970 to 15 million by 2030. 4 The financial burden of untreated mental illness in the United States has been estimated at $100 billion annually, of which nearly one-half has been attributed to older adults. 5,6 Psychiatric disorders in late-life, including MDD, Received September 29, 2012; revised April 29, 2013; accepted May 2, 2013. From Assistance Publique-Hôpitaux de Paris (AM, NH, J-PS, CL, FL), Service universitaire de Psychiatrie de l’adulte et du sujet âg e, Hôpitaux Universitaires Paris Ouest, Corentin Celton Hospital, Issy-les-Moulineaux, France; Universit e Paris Descartes (NH, YLS, CL, FL), Sorbonne Paris Cit e, Facult e de M edecine, Paris, France; INSERM U894 (NH, YLS, CL, FL), Centre de Psychiatrie et Neurosciences, Paris, France; and Assistance Publique-Hôpitaux de Paris (YLS), Department of Psychiatry, Louis-Mourier Hospital, Colombes, France. Send correspondence and reprint requests to Aude Manetti, M.D., Hôpital Corentin Celton, 4 parvis Corentin Celton, 92130 Issy-les-Moulineaux, France. e-mail: aude.manetti@ccl.aphp.fr Supplemental digital content is available for this article in the HTML and PDF versions of this article on the journal’s Web site (www. ajgponline.org). Ó 2014 American Association for Geriatric Psychiatry http://dx.doi.org/10.1016/j.jagp.2013.05.001 1292 Am J Geriatr Psychiatry 22:11, November 2014