The epidemiology of DSM-III-R bipolar I disorder in a general population survey.

BACKGROUND: Data are presented on the general population epidemiology of DSM-III-R bipolar I disorder in the United States.

METHODS: Data come from the US National Comorbidity Survey (NCS), a general population survey of DSM-III-R disorders. A modified version of the Composite International Diagnostic Interview was used to make diagnoses.

RESULTS: A small (N = 59) clinical reappraisal study showed that the only manic symptom profile that could validly be assessed with the CIDI is characterized by euphoria, grandiosity and the ability to maintain energy without sleep, which described approximately half of all clinically validated bipolar I cases in the NCS. Further analysis focused on this symptom profile, which involved N = 29 cases in the total sample. Lifetime prevalence was estimated to be 0.4% and 12-month prevalence only slightly lower. Caseness was negatively related to income, education and age, positively related to urbanicity, and elevated among the previously married, never married and non-whites. All cases reported at least one other NCS/DSM-III-R disorder and 59.3% reported that their episode of bipolar disorder (either mania or depression) occurred at a later age than at least one other NCS/DSM-III-R disorder. Although 93.2% of lifetime cases reported some lifetime treatment, only 44.7% of recent cases were in treatment.

CONCLUSIONS: The type of bipolar disorder examined here is highly chronic, co-morbid and impairing. Increased efforts are required to attract current cases into appropriate treatment. Methodological research is needed to develop more accurate measures of other bipolar symptom profiles for use in general population epidemiological studies.