Ž . Psychiatry Research 77 1998 131138 Electroencephalographic abnormalities in borderline personality disorder Jose Manuel De la Fuente a,  , Patrick Tugendhaft b , Nicolas Mavroudakis b ´ a Psychiatry Department, Erasme Hospital, Free Uni®ersity of Brussels, 808 Route de Lennik, B-1070 Brussels, Belgium b Neurology Department, Erasme Hospital, Free Uni®ersity of Brussels, 808 Route de Lennik, B-1070 Brussels, Belgium Received 2 May 1997; revised 18 September 1997; accepted 26 September 1997 Abstract Epilepsy and non-localized brain dysfunction have been invoked, among others, as underlying factors in borderline personality disorder. We have recorded 58 electroencephalograms in 20 borderline patients, first after complete drug washout and then under carbamazepine or placebo double-blind treatment. Taking into account only definite abnormal tracings, we found a 40% incidence of abnormal diffuse slow activity. No patient disclosed focal or epileptiform EEG features. Carbamazepine did not appear to modify the electroencephalogram.  1998 Elsevier Science Ireland Ltd. Keywords: Borderline personality disorder; Electroencephalography; Slow activity; Carbamazepine 1. Introduction. Ž . Borderline personality disorder BPD is a Ž well-recognized syndrome American Psychiatric  Corresponding author, Hopital psychiatrique de Lan- ˆ nemezan, Route de Toulouse, F-65300 Lannemezan, France. Tel.: q335 62 995525; fax: q335 62 995305. . Association, 1987 . Its main clinical features in- clude brief episodes of affective manifestations, brief psychotic episodes, emotional instability, im- pulsive and unpredictable behavior, frequent self-mutilations and altered interpersonal rela- tions. BPD has been associated with several psychi- atric and organic pathological conditions. Ž Schizophrenia Gunderson et al., 1975; Gunder- 0165-1781r98r$19.00  1998 Elsevier Science Ireland Ltd. All rights reserved. Ž . PII S0165-1781 97 00149-2