More reason to doubt benefits of HBOT

Doreen Granpeesheh and colleagues reported that a randomized trial of hyperbaric-oxygen therapy did not produce beneficial effects on children with Autism. The results of the study—double-blind, placebo controlled procedures, making it scientifically sound—showed no significant differences in direct observations of toy play, hyperactivity, appropriate vocalizations, vocal stereotypy, physical stereotypy, aggression, self-injury, property destruction or on standardized assessment employing a host of psychological measures.

Children in the treatment and control groups received 80 1-hour sessions in an HBOT chamber of, but only half of the children experienced the elevated level of supplemental oxygen while they were in the chamber. The two groups were matched for the number of hours of therapy (based on applied behavior analysis principles) that they received.

To be sure, it is difficult to argue from null findings. However, it is worth noting that this study uses rigorous procedures and strong measures, making it much more trustworthy that other research that has examined the benefit or lack of benefits of HBOT. I expressed reservations about another study of the effects of HBOT and interested readers may view EBD Blog’s earlier post about the Rossignol et al. study (see, additionally, the comments for other evidence questioning the benefits of HBOT).

Granpeesheh, D., Tarbox, J., Dixon, D. R., Wilke, A. E., Allen, M. S., & Bradstreet, J. J. (in press). Randomized trial of hyperbaric oxygen therapy for children with autism. Research in Autism Spectrum Disorders. Advance online publication. doi:10.1016/j.rasd.2009.09.014

Randomized trial of hyperbaric oxygen therapy for children with autism
Doreen Granpeesheh, Jonathan Tarbox, Dennis R. Dixon, Arthur E. Wilke, Michael S. Allen and James Jeffrey Bradstreet


Autism Spectrum Disorders (ASDs) are characterized by the presence of impaired development in social interaction and communication and the presence of a restricted repertoire of activity and interests. While numerous treatments for ASDs have been proposed, very few have been subjected to rigorous scientific investigation. Hyperbaric oxygen therapy (HBOT) has been recently popularized as a treatment for the symptoms of ASDs. The purpose of this study was to test the hypothesis that HBOT would have a beneficial effect on ASD symptoms in the context of a double-blind placebo-controlled trial. This randomized double-blind placebo-controlled trial compared HBOT used to deliver 24% oxygen at 1.3 atmospheric pressure (n = 18) to placebo (n = 16) in children with Autistic Disorder. Both direct observational measures of behaviors symptomatic of autism and standardized psychological assessments were used to evaluate the effects of the treatment. No differences were detected between HBOT and placebo groups across any of the outcome measures. The present study demonstrates that HBOT delivered at 24% oxygen at 1.3 atmospheric pressure does not result in a clinically significant improvement of the symptoms of Autistic Disorder.

The authors are affiliated with the Center for Autism and Related Disorders and the International Child Development Resource Center. The latter, with which author Bradstreet is associated, is an organization that promotes HBOT; I’m encouraged to see that it is participating in a serious scientific effort to examine this therapy.

3 Responses to “More reason to doubt benefits of HBOT”

  • This study is flawed. It only uses 1.3 ATA and 24% oxygen. This is barely above the normal 23% in the atmosphere. To guage the true effects of hyperbaric oxygen therapy, there must be 100% oxygen inhaled. I would also recommend a true hyperbaric chamber be used that will go to 1.5 – 1.75 ATA. All that was accomplished in this study is proof that treatment for altitude sickness does not help autistic children. Please do more research to see if what I am saying is true.

    Thanks and take care,


  • Ms. or Mr. MacLaughliin, thanks for the comment. Your concern about the ATA level is worth considering, but I’m not so sure about the reservations regarding the “true hyperbaric chamber.” I’ll comment first on the latter point and then move to the former.

    Because companies are selling portable hyperbaric chambers to parents and others who, understandably, are searching for cures for children whom they know (and often love), it seems quite reasonable to test whether such chambers improve outcomes. Given the results of this and Rossignol et al. study (see link in the original content) as well as the observations review by Mike Bennett (see comments on the Rossignol post), it’s looking pretty grim for portable tents. I’m surely not recommending that people buy ’em. Buy lots of folks on the Internet are hawking them; as of this evening, there are three paid advertisements that appear at the top of the results page when one searches “hbot autism” on Google.

    As to the dose effect, Mike Bennett made a similar observation. Maybe big O2 would make a difference. I shan’t be doing such research without the aid of a collaborator who really knows this sort treatment. I can write the features of the protocol that have to do with the design of such an experiment, the measures to be employed, and such. However, I don’t know enough about safety and advisability of submitting people (especially, vulnerable children) to such a treatment to be one who designs the independent variable for such a study.

    If you have the scientific chops to conduct such a study, why not apply to a funding agency to get the $$ to conduct it. In a paraphrase of the wonderful words of Mark Twain, it would be better to find out than to suppose.

    In scientific research, at least as far as I understand it (and you’re welcome to examine my work, as it’s available via just about any reasonable academic library), the burden of proof primarily lies with those who advocate hypotheses (in this case, the hypothesis that HBOT improves behavior—including social interactions and learning—of individuals with Autism). One of the good things about this and the Rossignol et al. study is that advocates of therapy have contributed to (perhaps not perfect, but) serious tests of the therapy.

  • There is at this time not many double blind placebo studies on the subject of brain injury, of which I group ASD in. However there is clnical evidence of brain healing that was not possible before HBOT and is relativly unknown to the medical community. Some of that evidence is on the Paul Harch web site, specifically the Curt Allen story.

    Please go to the website and watch the video of Curt Allen. Let me know what you think.

    These results are not possible with the GAMOW bags (portable altitude sickness bags), they are only possible with a chamber capable of 1.5 ATA and 100% O2.



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