On the prevalence of bipolar disorder in epilepsy.

Although mood disorders represent a frequent psychiatric comorbidity in epilepsy, data on bipolar disorder (BD) are still limited, and the role of possible specific confounding variables (seizures and antiepileptic drug therapy) has never been considered. Data for 143 adult outpatients with epilepsy assessed with the Mini International Neuropsychiatric Interview Plus Version 5.0.0 using the Epilepsy Addendum for Psychiatric Assessment, the Mood Disorder Questionnaire, and the Interictal Dysphoric Disorder Inventory revealed that 11.8% had the Diagnostic and Statistical Manual of Mental Disorders-based diagnosis of BD, only 1.4% of whom could be considered as having "pure" BD, because in all other cases BD symptoms were related to phenotype copies of BD such as interictal dysphoric disorder of epilepsy, postictal manic or hypomanic states, and preictal dysphoria.