Children with autistic spectrum disorders. I: Comparison of placebo and single dose of human synthetic secretin

Aims: To examine the effect of a single dose of human synthetic secretin (HSS) on behaviour and communication in children with autism spectrum disorder (ASD) using an objective measure of communication and social reciprocity and standardised rating scales. Methods: Randomised, crossover, double blind, and placebo controlled trial of a single intravenous dose of human synthetic secretin (HSS) 2 CU/kg. The 62 subjects ( 3 - 8 years) were assigned to group 1 ( saline placebo/HSS) or group 2 (HSS/saline placebo). Diagnosis was confirmed by ADI-R ( Autism Diagnostic Interview - Revised) algorithm. Severity of symptoms was rated using the CARS ( Childhood Autism Rating Scale). Outcome measures included Communication and Symbolic Behavior Scale ( CSBS), Ritvo Real-life Rating Scale, weekly Global Rating Scale ( GBRS) by parents and teachers, and daily log of gastrointestinal symptoms. The communication subscale of the CSBS, specifying communication function, reciprocity, and social-affective signalling was videotaped and scored by a blinded, trained observer. Results: Sixty one children completed the study. After randomisation, there were no significant differences in gender, race, age, and parent and teacher GBRS and Ritvo Scale between the two groups. Compared with placebo, secretin treatment was not associated with significant improvement of CSBS standard scores from baseline to 2 or 4 weeks post-infusion. Five children showed clinical improvement in standard scores: two after HSS and three after placebo. There were no significant changes in gastrointestinal symptoms after HSS or saline placebo. Conclusions: A single dose of intravenous human secretin is not effective in changing behaviour and communication in children with ASD when compared to placebo.