Risperidone Treatment In Children With Autism Spectrum Disorder And High Levels Of Repetitive Behavior

Inclusion Criteria: 1. Male or females of any race or ethnicity between the ages of 8 and 16 years, 2. Body weight greater than 20 kg body weight 3. DSM-IV diagnosis of Autistic Disorder, PDD, NOS, or Asperger's Disorder (established by clinical assessment, corroborated by standard cutoff scores on the Autism Diagnostic Interview and Autism Diagnostic Observation Schedule), as determined by ADI-R administered by raters who are trained to research reliability, and confirmed by an experienced and reliable clinician using DSM-IV-TR criteria. 4. Anticonvulsants used for the treatment of a seizure disorder will be permitted if the dosage has been stable for 4 weeks and the patient is seizure free for at least 6 months, 5. Clinical Global Impression (CGI) Severity score of at least 4; and subjects must also have a score greater than 7 on the first 3 items of the Compulsions Subscale of the Revised PDD CY-BOCS. 6. Ambulatory status (outpatient or day-treatment) at time of randomization 7. Subject must demonstrate a mental age \>18 months as determined by the Vineland Adaptive Behavior Scales. 8. Subjects must be free neuroleptics two weeks prior to baseline. Subjects who are on SSRIs or stimulants, must be on a stable dose for at least 4 weeks prior to baseline visit. 9. Subjects and their parents (guardians) must be judged reliable for medication compliance and must agree to keep appointments for study visits and tests as outlined in the protocol. Exclusion Criteria: 1. IQ below mental age of 18 months as measured by either the age-appropriate form of the Wechsler, the Revised Leiter, or the Mullen 2. Females with a positive Beta HCG pregnancy test, 3. Evidence of a prior adequate trial with risperidone (defined as duration of four weeks or more at a dose of at least 2 mg per day) 4. Evidence of hypersensitivity to risperidone (defined as allergic response \[e.g., skin rash\]) or potentially serious adverse effect (e.g., significant tachycardia) 5. Past history of neuroleptic malignant syndrome. 6. DSM-IV diagnosis of substance abuse. 7. A significant medical condition such as heart disease, hypertension, liver or renal failure, pulmonary disease, or unstable seizure disorder identified by history, physical examination or laboratory tests. 8. The use of any other psychotropic medication