Background:Several uncontrolled studies of hyperbaric treatment in children with autism have
reported clinical improvements; however, this treatment has not been evaluated to date with a
controlled study. We performed a multicenter, randomized, double-blind, controlled trial to assess
the efficacy of hyperbaric treatment in children with autism.
Methods:62 children with autism recruited from 6 centers, ages 2–7 years (mean 4.92 ± 1.21),
were randomly assigned to 40 hourly treatments of either hyperbaric treatment at 1.3 atmosphere
(atm) and 24% oxygen ("treatment group", n = 33) or slightly pressurized room air at 1.03 atm and
21% oxygen ("control group", n = 29). Outcome measures included Clinical Global Impression
(CGI) scale, Aberrant Behavior Checklist (ABC), and Autism Treatment Evaluation Checklist
Results:After 40 sessions, mean physician CGI scores significantly improved in the treatment
group compared to controls in overall functioning (p = 0.0008), receptive language (p < 0.0001),
social interaction (p = 0.0473), and eye contact (p = 0.0102); 9/30 children (30%) in the treatment
group were rated as "very much improved" or "much improved" compared to 2/26 (8%) of controls
(p = 0.0471); 24/30 (80%) in the treatment group improved compared to 10/26 (38%) of controls
(p = 0.0024). Mean parental CGI scores significantly improved in the treatment group compared
to controls in overall functioning (p = 0.0336), receptive language (p = 0.0168), and eye contact (p
= 0.0322). On the ABC, significant improvements were observed in the treatment group in total
score, irritability, stereotypy, hyperactivity, and speech (p < 0.03 for each), but not in the control
group. In the treatment group compared to the control group, mean changes on the ABC total
score and subscales were similar except a greater number of children improved in irritability (p =
0.0311). On the ATEC, sensory/cognitive awareness significantly improved (p = 0.0367) in the
treatment group compared to the control group. Post-hoc analysis indicated that children over age
Published: 13 March 2009
BMC Pediatrics2009, 9:21 doi:10.1186/1471-2431-9-21
Received: 20 January 2009
Accepted: 13 March 2009
This article is available from: http://www.biomedcentral.com/1471-2431/9/21
© 2009 Rossignol et al; licensee BioMed Central Ltd.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0),
which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
BMC Pediatrics 2009,9:21 http://www.biomedcentral.com/1471-2431/9/21
Page 2 of 15
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5 and children with lower initial autism severity had the most robust improvements. Hyperbaric
treatment was safe and well-tolerated.
Conclusion:Children with autism who received hyperbaric treatment at 1.3 atm and 24% oxygen
for 40 hourly sessions had significant improvements in overall functioning, receptive language, social
interaction, eye contact, and sensory/cognitive awareness compared to children who received
slightly pressurized room air.
Trial Registration:clinicaltrials.gov NCT00335790