Gender and bipolar illness

Background: For major depression and schizophrenia, gender differences have been reported in symptom expression and course of illness. Gender differences in bipolar disorder are becoming increasingly apparent, but have been less studied. Research data on these differences will help determine whether gender is important in influencing illness variables such as course, symptom expression, and likelihood of comorbidity. Method: Charts of 131 patients (63 women and 68 men) with a DSM-IV diagnosis of bipolar disorder admitted to the University of California Los Angeles Mood Disorders Program over a 3-year period were reviewed to gather data on demographic variables and course of illness and to assess differences in the illness across genders. Results: No significant gender differences were found in the rate of bipolar I or bipolar II diagnoses, although women were overrepresented in the latter category. Also, no significant gender differences emerged in age at onset, number of depressive or manic episodes, and number of hospitalizations for depression. Women, however, had been hospitalized significantly more often than men for mania. Further, whereas bipolar men were significantly more likely than bipolar women to have a comorbid substance use disorder, women with bipolar disorder had 4 times the rate of alcohol use disorders and 7 times the rate of other substance use disorders than reported in women from community-derived samples. Conclusion: For bipolar disorder, course of illness variables such as age at onset and number of affective episodes of each polarity do not seem to differ across genders. Women, however, may be more likely than men to be hospitalized for manic episodes. While both men and women with the illness have high rates of comorbidity with alcohol and other substance use disorders, women with bipolar disorder are at a particularly high risk for comorbidity with these conditions.