Risks associated with gender differences in bipolar I disorder.
BACKGROUND
Previous studies have demonstrated that bipolar patients may differ in several features according to gender, but a number of the differences found remain controversial.


METHODS
The demographic, illness course, clinical, comorbidity and temperament characteristics of a total of 1090 consecutive DSM-IV bipolar I manic inpatients were compared according to gender.


RESULTS
Bipolar illness in women was characterised by the predominance of depression, as indicated by a depressive polarity at onset, higher rates of mixed mania, more suicidal behaviour, and a greater number of temperaments with depressive propensities. In contrast, the manic component was found to predominate in men. Men also had an earlier onset of their illness. Women displayed more comorbidities with eating, anxiety, and endocrine/metabolic disorders, whereas men were more comorbid with alcoholism and other forms of substance abuse, neurological, and cancer disorders. The following independent variables were associated with male gender: being single (+), depressive temperament (-), excessive alcohol use (+), cyclothymic temperament (-), excessive other substance use (+), mood congruent psychotic features (+), and manic polarity at onset (+).


LIMITATIONS
The retrospective design and the sample being potentially not representative of the bipolar disorder population are limitations.


CONCLUSIONS
Findings from this study tend to confirm most of the differences previously observed among bipolar men and women. Furthermore, these results draw attention to the risks that may be specifically linked to gender differences in bipolar I patients.