title: Risperidone exerts potent anti-aggressive effects in a developmentally immature animal model of escalated aggression.
abstract: BACKGROUND
  Risperidone has been shown to be clinically effective for the treatment of aggressive behavior in children, yet no information is available regarding whether risperidone exhibits aggression-specific suppression in preclinical studies that use validated developmentally immature animal models of escalated aggression. Previously, we have shown that exposure to low doses of the psychostimulant cocaine-hydrochloride (.5 mg/kg intraperitoneally) during the majority of pubertal development (postnatal days [P]27-57) generates animals that exhibit a high level of offensive aggression. This study examined whether risperidone exerts selective aggression-suppressing effects by using this pharmacologic animal model of highly escalated offensive aggression.
  
  
  METHODS
  Experimental hamsters were tested for offensive aggression after the acute administration of risperidone (.05-1.0 mg/kg, intraperitoneally).
  
  
  RESULTS
  Risperidone dose-dependently reduced the highly aggressive phenotype, with a significant reduction observed at .1-.2 mg/kg for most aggressive responses measured. Experimental animals treated with higher doses of risperidone (.3-1.0 mg/kg) showed significant reductions in aggression and social interest toward intruders, indicating more general behavioral inhibition.
  
  
  CONCLUSIONS
  These studies provide evidence that risperidone exerts specific aggression-suppressing effects in a developmentally immature animal model of escalated aggression.
authors.affiliation: Behavioral Neuroscience Program, Department of Psychology, Northeastern University, Boston, Massachusetts 02115, USA.
authors.forename: Lesley A
authors.initials: LA
authors.lastname: Ricci
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Connor
authors.forename: Randall
authors.initials: R
authors.lastname: Morrison
authors.forename: Richard H
authors.initials: RH
authors.lastname: Melloni
mesh_terms: D000367:Age Factors; D000374:Aggression / Q000187:drug effects*; D000704:Analysis of Variance; D000818:Animals; D014150:Antipsychotic Agents / Q000494:pharmacology*; D006224:Cricetinae; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D007175:Impulsive Behavior / Q000188:drug therapy; D016018:Least-Squares Analysis; D008297:Male; D008647:Mesocricetus; D018967:Risperidone / Q000494:pharmacology*; D012920:Social Behavior Disorders / Q000188:drug therapy*
chemical_list: D014150:Antipsychotic Agents; D018967:Risperidone