Secretin Studies Fail to Show Efficacy in Autism Treatment

In 1998 a boy with autism and chronic diarrhea received an injection of the digestive hormone secretin to assess the function of his pancreas. Days later, the child’s parents noticed that he could hold still and interact better with adults. Parents of other autistic children thus sought out secretin injections for their youngsters. Some then reported that their children improved dramatically, some saw no effect, and still others attested that their children got worse, not better. So the pressing question was, Can secretin injections help children with autism or not?

The first scientific study designed to answer this question, which was reported in the December 9, 1999, New England Journal of Medicine, did not find that a single intravenous dose of synthetic secretin helped autistic children perform better on a battery of behavioral tests, including the Autism Behavior Checklist, than a saline injection did (Psychiatric News, February 4, 2000). Three subsequent scientific studies published on secretin, either in the synthetic form or in the porcine form (which is what had been used in most cases of autistic children receiving secretin), likewise failed to find a positive effect. And now a fifth one also has produced negative results. It was conducted by Thomas Owley, M.D., an assistant professor of child and adolescent psychiatry at the University of Chicago, and his colleagues and is reported in the November Journal of the American Academy of Child and Adolescent Psychiatry.

Owley and his coworkers conducted their study at sites in Illinois, California, and Utah. Fifty-six children with autistic disorder, ranging in age from 3 to 12 years, were randomized to receive either an intravenous dose of porcine secretin, followed by a saline injection four weeks later, or an intravenous dose of saline, followed by a dose of secretin four weeks later. Neither researchers nor subjects knew when the subjects were getting secretin or saline.

The children underwent detailed evaluations before receiving treatment, and then every two weeks thereafter, to determine whether their symptoms of autism showed any change. These evaluations continued until eight weeks after treatment to ensure that the investigators would not miss any positive effects.

Using a change in the Autism Diagnostic Observation Schedule social-communication score as a primary measure, the researchers found no statistically significant differences in the subjects’ social and communication skills when they received secretin compared with when they received the placebo. In certain secondary measures of autism, patients receiving secretin also showed no improvement when compared with when they received a placebo.

“Our study reiterates the need to perform careful studies of any new treatment—even one that appears promising—before routinely prescribing it to patients,” Owley said in a press statement released by the National Institute of Child Health and Human Development (NICHD) in conjunction with the publication of the study.

“These results, in addition to those from other secretin clinical trials, do not provide evidence to support using the hormone to treat the symptoms of autism,” Duane Alexander, M.D., director of NICHD, said in the same press statement.

The study was conducted as part of the Collaborative Network on the Neurobiology and Genetics of Autism, supported by the NICHD and the National Institute on Deafness and Other Communication Disorders. Additional support for the trial came from the National Institute of Mental Health and the University of California at Davis.

An abstract of the report, “Multisite, Double-Blind, Placebo-Controlled Trial of Porcine Secretin in Autism,” can be accessed on the Web at www.jaacap.com by searching under the issue “November 2001.” ▪