Reexamining associations between mania, depression, anxiety and substance use disorders: results from a prospective national cohort

Separate inheritance of mania and depression together with high rates of clinical overlap of mania with anxiety and substance use disorders provide a basis for re-examining the specificity of the prospective association of manic and depression episodes that is a hallmark of bipolar disorder. We analyzed information from 34 653 adults in Waves 1 and 2 of the National Epidemiologic Survey on Alcohol and Related Conditions, a longitudinal nationally representative survey of US adults interviewed 3 years apart. Psychiatric disorders were assessed by a structured interview. We used logistic regression analyses to estimate the strength of associations between Wave 1 manic episodes and Wave 2 depression, anxiety and substance use disorders controlling for background characteristics and lifetime Wave 1 disorders. Corresponding analyses examined associations between Wave 1 major depressive episode with manic episodes and other psychiatric disorders. In multivariable models, Wave 1 manic episodes significantly increased the odds of Wave 2 major depressive episodes (adjusted odds ratio (AOR): 1.7; 95% confidence interval: 1.3-2.2) and any anxiety disorder (AOR: 1.8; 1.4-2.2), although not of substance use disorders (AOR: 1.2; 0.9-1.5). Conversely, Wave 1 major depressive episodes significantly increased risk of Wave 2 manic episodes (AOR: 2.2; 1.7-2.9) and anxiety disorders (AOR: 1.7; 1.5-2.0), although not substance use disorders (AOR: 1.0; 0.9-1.2). Adults with manic episodes have an approximately equivalent relative risk of developing depression episodes and anxiety disorders. Greater research and clinical focus is warranted on connections between manic episodes and anxiety disorders.