Prevalence, Correlates, and Comorbidity of Bipolar I Disorder and Axis I and II Disorders: Results From the National Epidemiologic Survey on Alcohol and Related Conditions

Objective: To present nationally representative data on 12-month and lifetime prevalence, correlates, and comorbidity of bipolar I disorder.

Method: The data were derived from the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (N=43,093). Prevalences and associations of bipolar I disorder with sociodemographic correlates and Axis I and II disorders were determined.

Results: Prevalences of 12-month and lifetime DSM-IV bipolar I disorder were 2.0% (95% CI=1.82 to 2.18) and 3.3% (95% CI=2.76 to 3.84), respectively, and no sex differences were observed. The odds of bipolar I disorder were significantly greater among Native Americans, younger adults, and respondents who were widowed/separated/divorced and of lower socioeconomic status and significantly lower among Asians and Hispanics (p < .05). Men were significantly(p < .05) more likely to have unipolarmania and earlier onset and longer duration ofmanic episodes, while women were more likelyto have mixed and major depressive episodes andto be treated for manic, mixed, and major depressiveepisodes. Bipolar I disorder was found tobe highly and significantly related (p < .05) tosubstance use, anxiety, and personality disorders,but not to alcohol abuse.

Conclusion: Bipolar I disorder is more prevalent in the U.S. population than previously estimated, highlighting the underestimation of the economic costs associated with this illness. Associations between bipolar I disorder and Axis I and II disorders were all significant, underscoring the need for systematic assessment of comorbidity among bipolar I patients.’ ‹