Comorbidity between hypomania and substance use disorders

BackgroundBipolar disorder is associated with substance use and misuse. However, to date few studies have examined the relationship between hypomania and substance misuse and dependence in the general population.MethodsData come from the National Institute of Mental Health Collaborative Psychiatric Epidemiology Surveys (CPES), a set of multi-stage area probability samples of US adults (N=10,404). Multivariable linear and logistic regression was used to assess the relationship between DSM-IV hypomania and nicotine, alcohol, cannabis, cocaine, and prescription drug use. Models were adjusted for age, gender, education, and marital status. Stratified analyses and interaction terms were used to determine whether the relationship between hypomania and substance misuse varied by race/ethnicity.ResultsThe 12-month prevalence of hypomania was 0.5%. Hypomania was more common among African Americans (0.9%) relative to non-Hispanic Whites (0.5%) or other race/ethnicities (0.7%). Individuals with hypomania were 3.6 (95% CI: 1.5, 8.5) and 2.9 (95% CI: 1.3, 6.8) times more likely to also meet criteria for alcohol abuse/dependence and drug abuse/dependence relative to individuals without. The relationship between hypomania and substance use outcomes did not vary by race/ethnicity.LimitationsThe primary limitation of this study is its cross-sectional design, which precludes any inference about the causal nature of comorbid hypomania-substance use.ConclusionsHypomania is associated with increased likelihood of substance use and dependence/abuse across a broad range of substances. These associations were consistent across racial/ethnic groups. Findings indicate that even sub-syndromal conditions, such as hypomania, are significantly related to substance use and misuse in the community.