ELSEVIER Psychiatry Research 63 (1996) 231-232 PSYCHIATRY RESEARCH Case Report Cataplexy and the switch process of multiple personality disorder Maria C. La Via, Timothy D. Brewerton* Institute of Psychiatry, Medical University of South Carolina, 171 Ashley Avenue, Charleston, SC 294250742, USA Received 31 July 1995; accepted 10February 1996 Abstract A case history is presented of an l&year-old male with dissociative disorder and polysubstance abuse. The patient was observed to switch between three personalities, and the personality changes were often associated with symptoms of cataplexy. Both dissociative episodes and cataplexy are associated with strong affective stimuli. Similar reports in the literature are briefly reviewed. Keywords:Dissociative identity disorder; Muscular weakness; Substance abuse 1. Introduction Multiple personality disorder (MPD), now call- ed dissociative identity disorder, is a posttraumatic psychiatric disorder in which the individual’s con- sciousness is organized into a set of discrete dissociative states, each with its own state- dependent affects, body images, thoughts, memo- ries, and behaviors. Transitions between these states are abrupt and discontinuous compared with the smoother transitions between normal states of consciousness. Cataplexy is a neurologic condition in which the patient abruptly loses muscle tone and often falls, usually in response to some emotionally provoking stimulus. Mild episodes may show a drooping of the jaw, head nodding, or a sense of weakness obliging the patient to sit down or lean against a wall. The patient typically remains fully alert and aware of his surroundings. Attacks are of short duration, usually lasting several seconds and rare- ly more than a minute. Precipitation by emotional stimuli, particularly laughter, is usually strikingly evident in the history, but any strong emotion may bring on an attack. We here report a case in which cataplectic attacks appeared to be associated with the switch process in a patient with MPD. 2. Case description l Corresponding author, Tel: +1 803 7924092; Fax: +1 803 7924042. Mr. H. is an l&year-old male with a history of dissociative disorder and polysubstance abuse who 0165-1781/96/$15.00 0 1996 Elsevier Science IrelandLtd. All rights reserved PII SOl65-1781(96)02887-9