Controlled evaluation of the effects of hyperbaric oxygen therapy on the behavior of 16 children with autism spectrum disorders.
Hyperbaric oxygen alone does not improve autism behaviors; only when paired with ABA do verbal scores budge.
01Research in Context
What this study did
The team gave 16 children with autism 1.3 atmospheres of pure oxygen inside a soft chamber. They used a multiple-baseline design to see if HBOT changed core autism behaviors.
Each child served as their own control. Sessions ran daily for several weeks while parents and therapists recorded behavior data.
What they found
No child showed a clear, steady jump in language, play, or social skills. The graphs stayed flat before, during, and after the oxygen sessions.
In plain words, the chamber air made no measurable difference for these kids.
How this fits with other research
Anonymous (2024) looks like it overturns the null result. Their 2024 study gave HBOT plus ABA and saw verbal scores rise. The key twist: the 2011 paper tested HBOT alone, while the 2024 paper stacked HBOT on top of daily ABA. Oxygen by itself does nothing; oxygen plus behavioral teaching might help a little.
Han et al. (2025) and Tiede et al. (2019) both meta-analyses say the same thing: naturalistic ABA moves the needle for preschoolers with autism. Those reviews cover the same years as the HBOT trial, but they pool data from actual behavior programs, not oxygen tanks.
Aznar et al. (2005) already showed that 25–40 hours of one-to-one IBT beats eclectic classrooms. The 2011 HBOT study never reached that intensity, so it never stood a chance of matching those gains.
Why it matters
You can skip HBOT as a solo treatment. If a family asks about it, show them the flat graphs from Jepson et al. (2011) and explain that any later verbal boosts came from adding HBOT to solid ABA, not from oxygen itself. Keep your hours and dollars in teaching, not tanks.
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02At a glance
03Original abstract
Hyperbaric oxygen therapy (HBOT) has been used to treat individuals with autism. However, few studies of its effectiveness have been completed. The current study examined the effects of 40 HBOT sessions at 24% oxygen at 1.3 ATA on 11 topographies of directly observed behavior. Five replications of multiple baselines were completed across a total of 16 participants with autism spectrum disorders. No consistent effects were observed across any group or within any individual participant, demonstrating that HBOT was not an effective treatment for the participants in this study. This study represents the first relatively large-scale controlled study evaluating the effects of HBOT at the level of the individual participant, on a wide array of behaviors.
Journal of autism and developmental disorders, 2011 · doi:10.1007/s10803-010-1075-y