Background: Although recent studies have shown high rates of current and lifetime depression in HIV-infected patients, there is little systematic data on the occurrence of bipolarity in these patients.
Method: We compared 46 HIV patients with index major depressive episode (MDE) to an equal number of age- and sex-matched seronegative MDE patients, and systematically examined rates of DSM-III-R bipolar subtypes (enriched in accordance with Akiskal's system of classifying soft bipolar disorders).
Results: Although HIV and psychiatric clinic patients had comparable background in terms of familial affective loading, HIV patients had significantly higher familial rates for alcohol and substance use. The more important finding was the significantly higher proportion of HIV patients with lifetime bipolar II disorder (78%), and associated cyclothymic (52%) and hyperthymic (35%) temperaments; the findings were the same irrespective of HIV risk status (intravenous drug user vs. homosexual and other risk groups combined).
Limitations: The major methodologic limitation of our study is that clinicians evaluating temperament were not blind to affective diagnoses and family history. The comparison affective group was a sample of convenience drawn from the same tertiary care university facility.
Conclusion: The finding of a high rate of bipolar II disorder in HIV patients has treatment implications for seropositive patients presenting with depression. More provocatively, we submit that premorbid impulsive risk-taking traits associated with cyclothymic and hyperthymic temperaments may have played an important role in needle-sharing drug use and/or unprotected sexual behavior, leading ultimately to infection with HIV. Given their public health importance, these clinical findings and insights merit further investigation. In particular, systematic case-control studies, as well as other large scale studies with prospective methodology need to be conducted.