Clinical correlates of patients with rapid-cycling bipolar disorder and a recent history of substance use disorder: A subtype comparison from baseline data of 2 randomized, placebo-controlled trials

Objective: To compare clinical variables in patients with rapid-cycling bipolar I or II disorder and a recent history of substance use disorder (SUD). Method: Cross-sectional data from 2 studies of patients with rapid-cycling bipolar I disorder or rapid-cycling bipolar 11 disorder and a recent history of SUD were used to retrospectively assess the differences in clinical variables between the subtypes. The studies were conducted from November 1997 to February 2007 at University Hospitals Case Medical Center, Case Western Reserve University School of Medicine, Cleveland, Ohio. Extensive clinical interview and the Mini-International Neuropsychiatric Interview were used to ascertain DSM-IV diagnoses of rapid-cycling bipolar disorder, SUDs, and other Axis I disorders and to collect clinical variables. The Addiction Severity Index (ASI), Global Assessment Scale (GAS), and the Medical Outcomes Study 36-Item Short-Form Health Survey were used to measure the severity of impairment at the initial assessment. One-way analysis of variance or chi(2) was used for significance tests. A Bonferroni adjustment was applied for multiple comparisons. Results: Of 245 patients with rapid-cycling bipolar disorder (rapid-cycling bipolar I disorder, N = 191; rapid-cycling bipolar 11 disorder, N = 54) and a recent history of SUD, the demographics were similar. A significantly higher rate of panic disorder was observed in patients with rapid-cycling bipolar I disorder than in those with rapid-cycling bipolar 11 disorder (odds ratio = 3.72, 95% Cl = 1.66 to 8.32, p = .008). A significantly higher psychiatric composite score on the ASI was also found in patients with rapid-cycling bipolar I disorder than in those with rapid-cycling bipolar 11 disorder even after Bonferroni adjustment (p = .0007). There were no significant differences between the subtypes in the rates of previous hospitalization or suicide attempt, early childhood verbal, physical, or sexual abuse, lifetime substance abuse or dependence, the number of SUDs or mood episodes in the last 12 months, and total or other subscale scores on ASI and GAS. Conclusion: Except for the significantly higher rate of comorbid panic disorder and higher psychiatric composite scores on the ASI in patients with rapid-cycling bipolar I disorder than in those with rapid-cycling bipolar 11 disorder, the other clinical variables were similar between the 2 groups. Trial Registration: clinicaltrials.gov Identifiers NCT00194129 and NCT00221975.