Secretin, a hormone that some parents claim possesses almost magical properties as a treatment for autism, will be scientifically tested in large- scale trials starting later this month in Seattle and Denver.
Concurrent trials, funded by the National Institute of Child Health and Human Development (NICHD), will be conducted at the University of Washington's Center on Human Development and Disability (CHDD) and at the University of Colorado's Health Sciences Center. Fifty-one children between ages 3 and 12 and diagnosed with autism will be tested at each site.
Secretin is a naturally occurring human hormone produced in the small intestine that helps control digestion and is used in diagnosing gastrointestinal problems. Over the past six months secretin has been the focus of national media attention with some parents of autistic children saying hormone injections have resulted in improvements in their eye contact, alertness and use of language.
Autism is a severe developmental disorder that interferes with a child's ability to communicate or relate socially with other people. Afflicted individuals also have a restricted range of activities and interests. Autism is far more common than once believed, and as many as 550,000 Americans are estimated to have the disorder. Approximately 75 percent of children with autism also have some form of mental retardation.
The secretin trials project will be headed by Dr. Alan Unis, a UW associate professor of psychiatry and behavioral science and director of the developmental neuropsychiatry clinic at the CHDD, and Geraldine Dawson, a University of Washington psychology professor who also is directing a $7.3 million nationwide study to uncover the genetic and neurobiological causes of autism. In Denver, the trials team will be directed by Dr. Ed Goldson, professor of pediatrics at University of Colorado Health Sciences Center, and Sally Rogers, professor of psychiatry at the center and at JFK Partners.
About 100 children have received secretin injections as a treatment for autism and to diagnose digestive and gastrointestinal problems that frequently accompany the disorder, according to NICHD. But there have been no published studies evaluating the effectiveness of secretin.. However, some parents of autistic children have been vocal proponents of the hormone, citing its benefits in stories in the Wall Street Journal and on "Dateline" and "Good Morning America," among others.
In addition to the trials in Seattle and Denver, a number of other secretin trials are already underway or scheduled to start soon at the University of Chicago, the Southwest Autism Research Center in Phoenix, Scottish Rite Hospital in Atlanta, Children's Hospital in Philadelphia and at a site in North Carolina.
Two forms of secretin will be tested in the Seattle and Denver trials. Some children will be given an injection of natural secretin produced by pigs that is almost chemically identical to human secretin. Others will be given a synthetic secretin that is chemically equivalent to the pig hormone. A control group will be given a placebo injection of a saline solution.
Prior to receiving an injection, children selected to participate in the trials will be given a complete diagnostic evaluation that includes behavioral observation, language testing and a review of records and observations made by parents and teachers. A month following injection, the same evaluation will be repeated to note any changes in the children, according to Unis and Dawson.
Scientists have known for a long time, said Unis, that children with autism have high levels of blood serotonin, a hormone or chemical messenger similar to secretin. Both serotonin and secretin are produced in the small intestine and are found in the brain as well as the digestive tract. These hormones, also called neuropeptides, can effect sleep, appetite and other brain-regulated functions. He said that secretin stays in the blood for only a brief time, no longer than 20 minutes, but its effects have been noted weeks later.
One question the trials won't examine is the exact chemical composition of the natural form of pig secretin. It has been determined to consist of 60 percent secretin and 40 percent unknown components, which Unis said may be composed of broken bits of peptides. Researchers do not know if secretin or these unknown components are responsible for alleviating some of the symptoms of autism that have been alleged by parents.
However, Dawson, a pioneer in the early detection of autism, said that no proven medical treatment has yet been found that addresses autistic symptoms. There are medications that do relieve some conditions related to autism, such as hyperactivity and repetitive behaviors.
Dawson and Unis said that if the initial round of tests show secretin is beneficial, a larger study would follow to examine such important questions as the proper dosages of secretin and possible side effects.
Materials provided by University Of Washington. Note: Content may be edited for style and length.
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