A double-blind placebo-controlled crossover study of phenytoin in individuals with impulsive aggression

The present study examines the behavioral and psychophysiological effects o f phenytoin (PHT) in individuals who display impulsive -aggressive outburst s. In a double-blind placebo-controlled crossover design, individuals meeti ng previously established criteria for impulsive aggression were administer ed PHT and placebo during separate 6-week conditions. The efficacy measures used were the Overt Aggression Scale (OAS) and the Profile of Mood States (POMS). Psychophysiological measures (evoked potentials) were taken at base line and at the end of each 6-week condition. Photic stimulation was used t o evoke the mid-latency P1-N1-P2 waveform complex. Analysis indicated a sig nificant decrease in the frequency of im pul sive -aggressive outbursts dur ing PHT administration compared to baseline and placebo. Analysis of the ps ychophysiological data showed significantly increased PI amplitude and sign ificantly longer N1 latency during PHT administration. In addition, a reduc tion in N1 amplitude during PHT administration was also suggested. These fi ndings indicate reparation of physiological abnormalities previously observ ed in impulsive- aggressive individuals and imply more efficient sensory pr ocessing and effective orienting of attention. Taken together, these result s provide insight as to the physiological mechanisms by which PHT serves to ameliorate impulsive-aggressive behavior. (C) 2001 Elsevier Science Irelan d Ltd. All rights reserved.