Independent predictors for lifetime and recent substance use disorders in patients with rapid-cycling bipolar disorder: focus on anxiety disorders.

We set out to study independent predictor(s) for lifetime and recent substance use disorders (SUDs) in patients with rapid-cycling bipolar disorder (RCBD). Extensive Clinical Interview and Mini-International Neuropsychiatric Interview were used to ascertain DSM-IV Axis I diagnoses of RCBD, anxiety disorders, and SUDs. Data from patients enrolling into four similar clinical trials were used. Where appropriate, univariate analyses with t-test or chi-square were applied. Stepwise logistic regression was used to examine the relationship among predictor variables and lifetime and recent SUDs. Univariate analysis showed that patients with co-occurring anxiety disorders (n = 261) had significantly increased rates of lifetime (odds ratio [OR]= 2.1) and recent (OR = 1.9) alcohol dependence as well as lifetime (OR = 3.4) and recent (OR = 2.5) marijuana dependence compared to those without co-occurring anxiety disorder (n = 303). In logistic regression analyses, generalized anxiety disorder (GAD) was associated with increased risk for lifetime SUDs (OR = 2.34), alcohol dependence (OR = 1.73), and marijuana dependence (OR = 3.36) and recent marijuana dependence (OR = 3.28). A history of physical abuse was associated with increased risk for lifetime SUDs (OR = 1.71) and recent marijuana dependence (OR = 3.47). Earlier onset of first mania/hypomania was associated with increased risk for lifetime SUDs (5% per year), and recent marijuana dependence (12% per year) and later treatment with a mood stabilizer were also associated with increased risk for recent SUDs (8% per year). Positive associations between GAD, later treatment with a mood stabilizer, and early childhood trauma and history of SUDs suggest that adequate treatment of comorbid anxiety, early treatment with a mood stabilizer, and prevention of childhood trauma may reduce the risk for the development of SUDs in patients with bipolar disorder.