Comorbidity of Late-Life Depression in the United States: A Population-based Study

Objectives: This study sought to determine the clinical and sociodemographic correlates and the treatment-seeking rate of major depressive disorder (MDD), diagnosed 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 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions, a large cross-sectional survey (N = 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 interaction between rates of current somatic comorbidity, lifetime and 12-month psychiatric 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.