By Nestor Lopez-Duran PhD
Hello all, todays post is going to be the first of a series of 3 short weekly posts discussing 3 autism-related studies recently published in the Journal Pediatrics. All 3 studies are systematic reviews of the effectiveness of specific interventions for autism. That is, all 3 studies merged the results of all previous studies that have tested whether an intervention is effective or not in order to reach some overall conclusion.
The study I will review today potentially answers the question whether Secretin is an effective treatment for autism. Secretin is a gastrointestinal peptide used to treat peptive ulcers, but the drug became often used to treat autism after 3 children with autism were reported to have improved after receiving this drug for unrelated conditions (see Horvath K, Stefanatos G, Sokolski KN, WachtelR, Nabors L, Tildon JT. Improved social and language skills after secretin administration in patients with autistic spectrumdisorders. J Assoc Acad Minor Phys. 1998;9(1):9 –15).
After that report numerous studies of the effectiveness of this drug have used more appropriate research protocols (such as randomly assigning participants to receive the drug or a sugar pill) but have failed to replicate the original findings. That is, they seem to suggest that the intervention may not be effective.
So in a recent issue of the Journal Pediatrics a team from Vanderbilt University reviewed 7 large studies of Secretin. Each of these studies included at least 30 children under the age of 12 who had been diagnosed using DSM-IV criteria via the Autism Diagnostic Observation Schedule (ADOS). The studies examined whether Secretin helped the children with receptive and expressive language, gastrointestinal symptoms, adaptive behaviors, cognitive functioning, social skills, and fine motor skills.
So does Secretin work?
The authors of this review explained:
No studies revealed significantly greater improvements in measures of language, cognition, or autistic symptoms when compared with placebo. Study authors who reported improvement over time did so equally for both intervention and placebo groups.
The above statement means that when a study showed that children improved after receiving Secretin, the improvement was no different than the improvement seen in response to the sugar pill. In addition, the type of Secretin used (porcine or synthetic) did not make a difference. Simply, Secretin did not work as treatment for autism in any of the studies that used the proper research methodology.
The weight of the evidence against Secretin is such that the authors of this review argued that future studies on Secretin for autism are not warranted. Why? Because funding more research on Secretin means spending money in an already discredited treatment and such money would be better spent examining a more promising intervention.
The study: Krishnaswami, S., McPheeters, M., & Veenstra-VanderWeele, J. (2011). A Systematic Review of Secretin for Children With Autism Spectrum Disorders PEDIATRICS, 127 (5) DOI: 10.1542/peds.2011-0428