Autism, Autism and Mercury

Hyperbaric Oxygen Therapy for Autism

The chances are you already know what Hyperbaric Oxygen Therapy (HBOT) is but don’t recognise it by name. You normally see it in underwater action films or documentaries as the process used to treat the bends in divers. The bends is a potentially fatal problem caused when deep-sea divers come up to the surface too quickly. Patients are placed in a pressure vessel that replicates the pressures the body endures underwater in a pure oxygen environment.
Surprisingly this process is recognised as an effective treatment for other problems such as wounds and sores that won’t heal. It seems the oxygen rich, high pressure atmosphere stimulates the healing process. However HBOT is being recommend by some doctors and new-age therapists as a treatment for a wide range of problems including autism.
The Hyperbaric Medical Centre of New Mexico under Dr. Kenneth Stoller, who is also assistant clinical professor of pediatrics at the University of New Mexico School of Medicine, is one centre offering the treatment. Dr Stoller is firmly on the anti-mercury/thimerosal side of the “Does mercury cause autism?” debate.
When I first found out about HBOT I was extremely skeptical. There is no evidence it works with autistic childern and some proponents of HBOT promote a long list of conditions that HBOT can treat. I’ve found that a good rule of thumb is the longer the list of problems a treatment claims to help the less likely it actually helps. However it seems at least logical that increasing the supply of oxygen to the brain could stimulate neural growth and repair. Dr Stoller presented a paper, Hyperbaric Medicine and Brain Injured Children, to the US Government and contains some evidence to support his claims.
The one thing we can be sure about HBOT and autism is that there is no consensus or body of evidence to say it works. Anyone interested in pursuing this therapy should consider long and hard before undertaking this unproven treatment.
See also: FAQ from Hyperbaric Medicine Today magazine, The Age of Autism: Showdown in Santa Fe


  1. Hi Chris, Dr. Orac (who is a surgical oncologist) wrote on the issue earlier this month.

    “It’s obvious to me that hyperbaric oxygen (HO) is one of those altie therapies that has actual medical uses (usually for a limited number of conditions) but gets coopted as supposedly being great for everything, even for warding off the aging process….

    First off, let’s get one thing straight. There’s absolutely no good scientific evidence that HO does any good for autism. None. Nada. Zip. The whole idea behind HO is to treat diseases for which decreased blood flow or a low oxygenation is major part of the pathophysiology and for which higher oxygen tension might reasonably be thought to help. This also includes conditions for which high oxygen tension can displace a specific toxin from a binding site, like CO bound to hemoglobin. That means that HO is useful for nonhealing wounds, decompression sickness, severe anaerobic bacterial infections, necrotizing fasciitis (the “flesh-eating” bacterial infection), or carbon monoxide poisoning. [Orac note: That’s where I had experience with this therapy during my residency: in the treatment of burn patients suffering from CO poisoning.] There’s also evidence that it can be helpful in increasing the efficacy of radiation therapy in certain cancers, but only for head and neck tumors.

    It’s only marginally scientifically plausible that HO would be good for autism. In fact, some evidence in the literature suggests that increased oxidative stress may have relevance to the pathophysiology autism. If that is actually true, then HO might potentially even be harmful to autistics. (Certainly the known possibility of neurotoxicity from HO should give any parent contemplating this therapy for autism pause.) However, there are also studies that suggest decreases in regional cerebral bloodflow in autistics, but the significance of these findings are unclear. Even if these results are consistent and confirmed, it does not necessarily follow that hyperbaric oxygen will do anything to reverse the pathophysiology. In any case, my team looked and looked and couldn’t find one trial, one scientific paper, or one bit of convincing evidence that it does anything. Only testimonials. A PubMed search on “hyperbaric oxygen” and “autism” fails to turn up a single hit….

    For diseases for which preclinical data suggests that HO might help, HO can at best be considered experimental and should not be used outside of clinical trials. For diseases for which there is no such data, then it shouldn’t even be considered. Of course, you will hear testimonials otherwise, but remember that testimonials generally exist to sell a product.”

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