Differential interactions between comorbid anxiety disorders and substance use disorder in rapid cycling bipolar I or II disorder.

Objective: Anxiety disorders (AD) and substance use disorders (SUD) commonly co-occur with bipolar disorder. This study was undertaken to assess AD-SUD-bipolar subtype interactions.

Methods: Extensive clinical interview and MINI were used to ascertain DSM-IV diagnoses of rapid cycling bipolar I (RCBPDI) or II (RCBPDII) disorder, SUDs, and ADs including generalized anxiety disorder (GAD), panic disorder (PD), and obsessive-compulsive disorder (OCD). Data at the initial assessment of four studies was used to compare the prevalence differences in ADs between RCBPDI and RCBPDII by using protocol-defined SUD categories, "Never," "Lifetime, but not recent," or "Recent."

Results: Five-hundred sixty-six of 568 patients (RCBPDI n=320, RCBPDII n=246) were eligible for analyses. In the "Never" group (n=191), patients with RCBPDI and RCBPDII had similar risk for ADs. In the "Lifetime, but not recent" group (n=195), RCBPDI patients had significantly higher risks for GAD (OR=3.29), PD (OR=2.95), but not OCD, compared with their RCBPDII counterparts. Similarly, in the "Recent" group (n=180), RCBPDI patients also had significantly higher risks for GAD (OR=3.6), PD (OR=3.8), but not OCD, compared with their RCBPDII counterparts.

Limitations: Data were cross-sectional and not all ADs were included.

Conclusion: In this large cohort of patients with rapid cycling bipolar disorder, risk for having GAD, PD, but not OCD increased significantly in patients with bipolar I disorder compared to their bipolar II counterparts when a history of SUD was present. However, there were no significant differences in the risk for GAD, PD, or OCD between the subtypes among patients without a history of SUD.