Comorbidity of migraine and psychiatric disorders among substance-dependent inpatients.

Background: Limited and conflicting data exist regarding the prevalence of psychiatric disorders, particularly substance use disorders (SUDs), among migraineurs in inpatient clinical settings.

Methods: As part of a larger cross-sectional study, 181 substance-dependent inpatients completed a structured psychiatric interview and measures of psychiatric symptoms and migraine. Standardized mean differences were used to quantify differences between inpatients with and without migraine across 4 domains of predictors (demographic variables, non-SUD psychiatric diagnoses, specific SUDs, and self-reported psychiatric symptoms). The predictors within each domain that best discriminated between the migraine and no-migraine groups were identified using a classification tree approach with Bonferroni corrections. These candidate predictors were subsequently entered into a multivariate logistic regression to predict migraine status, which was then replicated using bootstrapping of 500 samples. Associations between migraine status and SUD treatment dropout were also examined.

Results: Forty-four of the 181 (24.3%) participants met criteria for migraine. Migraineurs were more likely to be female (34.8% vs. 18.3%) and reported higher levels of current anxiety symptoms (mean [standard deviation]: 19.7 [11.0] vs. 11.3 [10.3]). Having a lifetime diagnosis of generalized anxiety disorder (56.8% vs. 27%, odds ratio 3.47, 95% confidence interval [CI] 1.39-10.58) or a current diagnosis of alcohol dependence (45.5% vs. 24.1%, odds ratio 3.79, 95% CI 1.63-13.62) was associated with more than a 3-fold risk of migraine. These 4 variables in combination were forced into the final multivariate model, which differentiated well between those with and without migraine (area under the receiver operating characteristic curve = 0.81; 95% CI 0.73-0.88). Migraine was not differentially associated with increased risk for SUD treatment dropout (13.6% vs. 16.1% dropout among those without migraine).

Discussion: A history of generalized anxiety disorder, high levels of current anxiety symptoms, and current alcohol dependence are the strongest psychiatric predictors of migraine status among substance-dependent inpatients. However, migraine status is not associated with SUD treatment dropout.