Secretin is a hormone that helps in digestion. Currently, the FDA only approves it for this use. In the 1990s there were a few reports of autistic people improving after taking it. However, since then many studies have been done. No differences in behavior have been found. People who take secretin are the same as those who take just sugar pills. For this reason, secretin is not recommended as a treatment for autism or other PDDs.
Adapted from National Institute of Child Health and Human Development (2005). Autism Overview: What We Know. NIH Pub. No. 05-5592, May 2005. Accessed on April 4, 2006 at http://www.nichd.nih.gov/publications/pubskey.cfm?from=autism.