Secretin as a treatment for autism: a review of the evidence.

Secretin is used in the United States for diagnosis of pancreatic gastrointestinal (GI) dysfunction and disease. Repeated therapeutic use has not been approved. Widespread interest in secretin as a treatment for autism followed media reports of behavioral improvements in an autistic child who received the hormone during a GI diagnostic procedure. International demand for secretin soared in the absence of experimental evidence of its efficacy for autism. This review presents a brief history of secretin's rise to popularity and summarizes research on secretin as a treatment for autism. Seventeen studies are reviewed comparing the effects of secretin forms, dosage levels, and dosing intervals on outcome measures with approximately 600 children. Twelve of 13 placebo-controlled studies failed to demonstrate the differential efficacy of secretin. Implications for advocating treatment in the absence of empirical evidence are discussed.