Bipolar Disorder Is Associated With an Increased Risk of Sexually Transmitted Infections: A Nationwide Population-based Cohort Study

Background: Previous studies have suggested that sexually transmitted infections (STI) tend to increase in patients with bipolar disorder during a manic or hypomanic episode. However, in the long-term course of this disease, it is unclear whether patients with bipolar disorder have a higher risk of incident STI. Methods: Using the National Health Insurance Research Database of Taiwan, 3721 patients with bipolar disorder and 14,884 controls without bipolar disorder matched by gender and age were enrolled between 2000 and 2010 and followed up until the end of 2013. Participants who developed any STI (human immunodeficiency virus [HIV], syphilis, genital warts, gonorrhea, chlamydial infection, and trichomoniasis) during the follow-up period were identified. Cox regression analysis was performed to examine the risk of STI between patients with bipolar disorder and comparative controls. Results: Patients with bipolar disorder were prone to develop STI (hazard ratio [HR], 1.67, 95% confidence interval [95% CI], 1.27-2.18) especially for HIV (HR, 3.59; 95% CI, 1.16-11.08) and syphilis (HR, 2.26; 95% CI, 1.06-4.85). In addition, this study found that the incidence of STI was higher among women than men (HR, 1.83; 95% CI, 1.41-2.39). Conclusions: This study shows that bipolar disorder is associated with an increased risk of developing STI, which has direct implications for the development of targeted prevention interventions or regular sexual health screening in mental health clinics to reduce the disproportionate burden of HIV and other STI in patients with bipolar disorder.