Low anxiety disorder comorbidity rate in bipolar disorders in Han Chinese in Taiwan

Objectives: Studies report high comorbidity of lifetime anxiety disorders with bipolar disorders in Western patients, but it is unclear in Taiwan. The authors explored the comorbidity of anxiety disorders in different bipolar disorder subtypes in Han Chinese in Taiwan. Methods: Three hundred twenty-five patients with bipolar disorder (bipolar I: 120; bipolar II: 205) disorder were recruited from two general medical outpatient services. They were evaluated and their diagnoses confirmed by a psychiatrist using the Chinese version of the Modified Schedule of Affective Disorder and Schizophrenia-Lifetime. The exclusion criteria were: any DSM-IV-TR Axis I diagnosis, other than bipolar disorder, being outside the 18-65-year-old age range, any other major and minor mental illnesses except anxiety disorder, any neurological disorders or organic mental disorders. Results: Thirty-two (26.7%) of patients were comorbid with lifetime anxiety disorder and bipolar I, 80 (39.0%) with lifetime anxiety disorder and bipolar II, 7 (5.8%) were comorbid with two or more anxiety disorders and bipolar I, and 27 (13.2%) with two or more anxiety disorders and bipolar II. Conclusion: That more than twice as many bipolar II than bipolar I patients reported two or more anxiety disorders implies that the complication is more prevalent in bipolar II patients.