A Study of the Safety and Effectiveness of Risperidone for the Treatment of Conduct Disorder and Other Disruptive Behavior Disorders in Children Ages 5 to 12 With Mild, Moderate, or Borderline Mental Retardation

Inclusion Criteria: * Meets Axis I diagnosis criteria for Conduct Disorder or Oppositional Defiant Disorder or Disruptive Behavior Disorder not otherwise specified (DSM-IV, Diagnostic and Statistical Manual of Mental Diseases, 4th edition) and has a total rating of \>=24 on the Nisonger Child Behavior Rating Form (N-CBRF) Conduct Problem Subscale. (Patients with conduct disorder who also meet DSM-IV criteria for Attention Deficit/Hyperactivity Disorder (AD/HD) are eligible.) * meets DSM-IV Axis II diagnosis criteria for Mild Mental Retardation, Moderate Mental Retardation or Borderline Intellectual Functioning (diagnoses that represent intelligence quotients \[IQs\] ranging from 35 to 84) Exclusion Criteria: * DSM-IV diagnosis of Pervasive Development Disorder, Schizophrenia, or Other Psychotic Disorders * head injury as cause of mental impairment * seizure disorder currently requiring medication * history of tardive dyskinesia (a condition of uncontrollable movements of the tongue, lips, face, trunk, hands and feet that is seen in patients receiving long-term medication with certain types of antipsychotic drugs) or neuroleptic malignant syndrome (a rare psychotropic-drug reaction, which may be characterized by confusion, reduced consciousness, high fever or pronounced muscle stiffness) * known hypersensitivity, intolerance, or unresponsiveness to risperidone.