Risk factors for postoperative depression in 150 subjects treated for drug-resistant focal epilepsy.

Objective.The primary goal was to identify risk factors for post-surgical depression in subjects operated on for drug-resistant epilepsy. Secondary goals were to confirm the high rate of depression in subjects suffering from epilepsy (prior to surgery) and to look for first post-surgical depressive episode.Methods.Case series study of 150 subjects surgically treated for partial epilepsy (side of surgery: 72 right, 78 left; site of surgery: 97 Unilobar Temporal, 17 Unilobar Frontal, 14 Posterior, 22 Multilobar). All subjects routinely had three psychiatric evaluations: before surgery (baseline) and at 6 and 12 months after surgery. Psychiatric diagnoses were made according to DSM-IV-TR criteria. Bivariate (Fisher exact test and Kruskal–Wallis rank sum test) and multivariate (logistic regression model fitting) analyses were performed.Results.Thirty-three (22%) subjects had post-surgical depressive episodes, 31 of them in the first 6 months. Fourteen out of 33 experienced depression for the first time. Post-surgical depressive episodes are not associated with gender, outcome on seizures, side/site of surgical resection, histological diagnosis, psychiatric diagnoses other than depression. Depressive episodes before surgery and older age at surgery time are risk factors for post-surgical depression (p = 0.0001 and 0.01, respectively, at logistic regression analysis). No protective factors were identified.Conclusions.Our data show that lifetime depressive episodes and older age at surgery time are risk factors for post-surgery depression. Moreover, a prospective study could be useful in order to assess whether depression is really a consequence of surgery