Psychotic episodes during zonisamide treatment

Several articles have appeared over the last years devoted to mental side e ffects during zonisamide (ZNS) treatment. In this study, we were particular ly interested in psychotic episodes. Seventy-four epileptic patients with a history of ZNS treatment were surveyed retrospectively over the period spa nning 1 March 1984 to 30 June 1994. They were divided into two groups accor ding to the presence or absence of psychotic episodes during ZNS treatment. We analysed various factors pertaining to psychotic episodes during ZNS tr eatment. Of the 74 patients 14 had psychotic episodes. We found that the in cidence of psychotic episodes during ZNS treatment was several times higher than the previously reported prevalence of epileptic psychosis, and that t he risk of psychotic episodes was higher in young patients. In 13 patients, psychotic episodes occurred within a few years of commencement of ZNS. In children, obsessive-compulsive symptoms appeared to be related to psychotic episodes. It is important to terminate ZNS as soon as possible if psychoti c episodes develop and never restart, even if seizures become worse. It can not definitely be proved that ZNS causes psychotic episodes, as information on mental side effects during ZNS monotherapy is scant, but it does appear likely that ZNS contributes to psychotic episodes during polytherapy. (C) 2000 BEA Trading Ltd.