PurposeThe aim of this study was to evaluate the prevalence of comorbid bipolar disorder (BD) among migraineurs and the impact of migraine–BD comorbidity on disease characteristics.Patients and methodsA total of 120 adult patients diagnosed with migraine at a single tertiary care center were included in this cross-sectional study. Data on sociodemographic and migraine-related characteristics, family history of psychiatric diseases, comorbid psychiatric diseases, and first-episode characteristics were recorded. Mood Disorders Diagnosis and Patient Registration Form (SCIP-TURK), Mood Disorder Questionnaire (MDQ), and Hypomania Checklist-32-Revised (HCL-32-R) were applied to all patients by experienced clinicians, and clinical diagnoses were confirmed using Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I). Migraine Disability Assessment Scale (MIDAS) was used to evaluate the headache-related disability. Study parameters were compared between migraineurs with and without comorbid BD.ResultsThe diagnosis of comorbid BD was confirmed in 19.2% of migraineurs. A significantly higher percentage of patients with comorbid BD than those without comorbid BD had family history of BD (39.1% vs 6.2%, P<0.001), suicide attempt (30.4% vs 5.2%, P<0.001), and physical abuse (52.2% vs 26.8%, P=0.019). MIDAS scores were significantly higher (50.6 [43.2] vs 33.8 [42.7], P=0.0422) in migraineurs with comorbid BD than in those without comorbid BD. Multivariate logistic regression model revealed that a positive family history of type I BD (odds ratio [OR], 14.42; 95% confidence interval [CI], 2.94–70.73; P=0.001) and MIDAS scores >30 (OR, 3.69; 95% CI, 1.12–12.19; P=0.032) were associated with 14.42 times and 3.69 times increased likelihood of BD, respectively.ConclusionOur findings revealed comorbid BD in a remarkable percentage of migraineurs and a higher likelihood of having BD in case of a positive family history of type I BD and MIDAS scores >30. Comorbid BD was associated with a higher rate for a family history of BD, suicide attempt, and childhood physical abuse as well as aggravated migraine-related disability among migraineurs. Migraineurs with and without comorbid BD showed similar sociodemographic and migraine disease characteristics as well as similar high rates for comorbid anxiety and first-episode depression.