Secretin and Autism

One of the currently controversial treatments for autism is the use of the neurotransmitter secretin. Since the mid-90s, there have been numerous anecdotal reports that treatment with secretin results in amazing and immediate improvements in many autistic children and adults.

Secretin is found in the gastrointestinal tract, where it helps the body to digest food better. Human secretin is used to help doctors diagnose and treat stomach and digestive problems, and is approved by the FDA for that purpose.

More specifically, secretin is a peptide hormone produced in the S cells of the duodenum in the crypts of Lieberkuhn. Its primary effect is to regulate the pH of the duodenal contents via the control of gastric acid secretion and buffering with bicarbonate. It was also the first hormone ever to be discovered.

So how did a protein thats used by the body in the digestive process end up being touted as an effective treatment for autism?

The Digestive Connection

First, you need to know that many children with disorders in the autism spectrum also have digestive and intestinal disorders, and research has shown that a lot of those have deficiencies of secretin and other proteins used in digestion. In 1998, doctors from Maryland published an article in the Journal of the Association for Academic Minority Physicians about three children with autistic spectrum disorders. Within five weeks of receiving intravenous infusions of secretin to help regulate their digestion, all three showed “a dramatic improvement in their behavior, manifested by improved eye contact, alertness, and expansion of expressive language.”

By October of 1998, the National Institutes of Health had posted their position on the use of secretin to treat autism which essentially said that it does not have an official position. Specifically, the letter states that any use other than for gastro-intestinal treatment is considered an ‘off-label use, for which there have been no safety or efficacy (effectiveness) studies.

It goes on to state, however, that there has been one small safety study that seems to suggest that a single dose treatment of secretin is safe, in that it has no unwanted side effects, and invites researchers to submit applications for funding research.

No Effect Found

Then in November of 2001, the Journal of the American Academy of Child and Adolescent Psychiatry reported that further studies with double-blind placebos had shown that secretin has no effect on autism, and that the improvements in children who were given secretin were no better than in those who were given a placebo.

A 2004 meta-analysis of 15 double-blind, randomized, controlled trials of secretin for treatment of subjects with autism spectrum disorders concluded:

“Almost none of the studies reported any significant effects and none concluded that secretin was effective. At this time there is no robust evidence that secretin is an effective treatment for pervasive developmental disorders.”

Hope Lingers

That was not the last word, however. All over the country, parents of children with autism spectrum disorders are still anecdotally reporting significant improvements in speech, behavior and attention in children who are given secretin. Because so little is know about the causes of autism, there is a possibility that there is a specific sub-group of children with autism who may benefit from the use of secretin.

Currently, it is not a recommended treatment for autism in general. Those who do advocate its use suggest that it be used in the specific sub-group of children who might benefit from its approved use to treat gastrointestinal disorder.

Image: Thomas Hawk/Flickr