Depression More Prevalent Now Than 20 Years Ago

Hasin DS, Goodwin RD, Stinson FS, Grant BF. Epidemiology of major depressive disorder: results from the National Epidemiologic Survey on Alcoholism and Related Conditions. Arch Gen Psychiatry. 2005;62:1097-1106.

About 13% of Americans have had at least one episode of major depressive disorder (MDD) in their lifetime--showing an increased prevalence of the condition since the 1980s, report researchers who analyzed data from the National Epidemiologic Survey on Alcoholism and Related Conditions. "Given the seriousness of MDD, the importance of information on its prevalence, demographic correlates, and psychiatric comorbidity cannot be underestimated," Hasin and colleagues contend.

The survey encompassed face-to-face interviews with 43,093 civilian, noninstitutionalized persons 18 and older. The structured diagnostic format was designed to identify both lifetime and 12-month MDD, while ruling out cases of bereavement and differentiating primary disorders from those related to a medical condition or substance abuse.

Prevalence of lifetime and 12-month MDD was 13.23% and 5.28%, respectively. Rates for both types of MDD were higher in women, Native Americans, and persons who were middle-aged or widowed, separated, or divorced.

Women were at twice the risk of men for lifetime MDD. Compared with white persons, Native Americans had a greater risk for lifetime MDD (odds ratio [OR], 1.5), while those of Asian, Hispanic, or black ethnicity had lower rates (ORs, 0.6, 0.6, and 0.7, respectively). Persons who were widowed, separated, or divorced were 2.2 times as likely as their married or cohabiting counterparts to have lifetime MDD.

About 60% of persons with MDD reported ever being treated specifically for the condition, with women more likely than men to have received treatment. Almost 10% of patients with MDD had ever required hospitalization. A three-year gap between onset of MDD and first treatment was noted, as mean age at onset was 30.4 years and mean age at treatment commencement was 33.5 years.

The association between both 12-month and lifetime MDD and comorbid conditions is displayed in the table (below). The researchers note that MDD was more strongly associated with alcohol, drug, or nicotine depen­ dence than with abuse of these substances.

Noting that MDD "is treated increasingly in the primary care sector," the authors stress that clinicians need information on treating comorbid MDD and substance dependence. They also suggest that future research investigate, among other things, what protective factors account for the low prevalence of MDD in some ethnic groups.