A soon-to-published study by the Center for Autism & Related Disorders (CARD) finds that "24% oxygen at 1.3 atmospheric pressure does not result in a clinically significant improvement" in children with autism.
The study design essentially replicates and refutes Rossignol, in whose work we and many others were encouraged to see promising results using room air at mild pressure. The CARD group studied about half as many subjects (34 versus Rossignol's 61), and neither their news release nor their abstract discloses the number or duration of treatments, so we need to learn more. We've placed our call to the principal investigator and will report what he teaches us.
One thing we know for sure until then: We'd like to see some bright young investigator run the oxygen up to 100%, pump the chamber up to truly hyperbaric pressure, adequately power and size the trial, and publish the results in a proper peer-reviewed journal. Not that we think that'd be a cinch.