Anger is a distinctive feature of epilepsy patients with depression.

Controversy exists regarding the similarity between depression as seen in patients with epilepsy and in those with idiopathic major depression. The objective of this study was to examine whether anger is a distinctive feature of depression in epilepsy. Participants included 487 adult patients with epilepsy (study group) and 85 patients with idiopathic major depression according to Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) criteria, and without other neurological complications (control group). All participants completed the Inventory of Depressive Symptomatology Self-Report (IDS-SR) and the Buss-Perry Aggression Questionnaire (BAQ). The IDS-SR is a self-report questionnaire that measures depression severity and assesses all symptoms of depression as defined by the DSM-IV. The BAQ is a self-rating scale designed for assessing aggression. After examining potential confounding factors (i.e., demographic and clinical variables) using a multivariate linear regression model, BAQ scores were compared between the study (n = 85) and control groups (n = 54) for patients with moderate or severe depression using established cut-off points (IDS-SR score > 25). BAQ scores were significantly higher in the study group (P = 0.009). Among the BAQ subscales, only anger showed a statistically significant difference (P = 0.013). Although a significant correlation was revealed between the IDS-SR and BAQ scores in the study group, no such correlation was found in the control group. Thus, anger might be a constituent component of depression among epilepsy patients, but not among idiopathic major depression patients.