Autism is a disorder characterized by impairments of social interactions, verbal and nonverbal communication, and preoccupation with unusual activities or interests, particularly stereotyped or repetitive movements. This debilitating disorder is estimated to occur in 2 to 10 of every 10,000 births. A primary focus in pyschopharmacological intervention has been to treat specific associated symptoms, such as hyperactivity, aggressiveness, and temper tantrums; there are few pharmacologic treatments directed toward core autistic symptoms.

Secretin is a gut hormone with binding sites in the brain. Previous research has described three patients with autism who underwent diagnostic endoscopy for gastrointestinal complaints and experienced dramatic improvement in autistic symptoms following the administration of intravenous secretin given as part of endoscopy. Though the results of this single, uncontrolled study have limited interpretive value, many autistic children have been exposed and continue to be exposed to this potential treatment in an uncontrolled manner. This double blind, placebo-controlled trial will evaluate the safety and efficacy of secretin for the treatment of autism.

Participants will be randomly assigned to one of three treatment groups: synthetic porcine secretin (sPS), biologically derived porcine secretin (bPS), or placebo. Each participant will be given an initial intravenous dose of 0.1 ml of their assigned treatment at the appropriate dose (0.2 ug for sPS and 1 CU for bPS). If no allergic reaction occurs within one minute, the participants will continue in the study and receive the full remaining dose over one minute. Participants will be evaluated one week before and four weeks after infusion for social, communication, and behavioral functioning as measured by Autistic Diagnostic Observation Schedule Generic (by blinded raters); Rimland Questionnaires (by parents and teachers); Expressive Vocabulary Test; MacArthur Communication Inventory (by parents and teachers); and Aberrant Behavior Checklist (by parents and teachers). Participants will also have a physical exam and blood and urine tests. After completion of preliminary data analysis, placebo patients will be offered open label therapy if appropriate.