ARI Publication 40 – 2013 Version

Research on Treatment:

There are several open-label studies of HBOT therapy for children, and most suggest that HBOT
therapy might be helpful, but one open-label study with rigorous pre/post assessment showed no
benefit. There are also two randomized, double-blind, placebo-controlled studies, with one study
showing statistically significant benefit in one of the measures but not the others, and the other
study showing no benefit. Two recent reviews of these studies are Rossignol, et al 2012 and
Ghanizadeh 2012.

Rossignol DA, et al, Hyperbaric oxygen treatment in autism spectrum disorders, Med Gas Res. 2012
Jun 15;2(1):16.

Ghanizac/eh A Hyperbalic oxygen therapyfor treatmentofdJildren with auUsm: a systemaUcreviewofrc,ndomized
trials Med Gas Res. 2012; 2: 13

Open-label studies:
Three small open-label studies involved 6-10 children with autism, and they generally reported
some improvements in autistic symptoms and therapy was well tolerated.

Rossignol DA, Rossignol LW: Hyperbaric oxygen therapy may improve symptoms in autistic children.
Med Hypotheses 2006, 67(2):216-228.
Chungpaibulpatana J, et al., Hyperbaric oxygen therapy in Thai autistic children. J MedAssoc
Thai 2008, 91(8):1232-1238.
Bents;. et al., Briefreport: Hyperbaric oxygen therapy (HBOT} in children with
autism spectrum disorder: a clinical trial. J Autism Dev Disord. 2012 Jun;42(6):1127-32.

One open-label study involved eighteen children with autism, ages 3-16 years, who received 40
hyperbaric sessions (45 minutes each) over 9 weeks. Six children received 1.5 atmospheres (atm)
and 100% oxygen, and 12 children received 1.3 atm and 24% oxygen. Both groups had modest
improvement in social responsiveness (communication, motivation, and mannerisms) and overall
autism severity (language, sensory/cognitive, and health/physical behavior). Pre and post blood
tests revealed a large improvement in CRP CC-Reactive Protein, a general marker of inflammation),
primarily in the 3 children who had very high levels. Measurements of oxidized glutathione (GSSG)
did not change, but measurements of total and free glutathione decreased, which is unfavorable.
This suggests that glutathione therapy should be done prior to HBOT. HBOT therapy was generally
well tolerated.

Rossignol DA, et al., The effects ofhyperbaric oxygen therapy on oxidative stress, inflammation, and
symptoms in children with autism: an open-labelpilot study. BMC Pediatr 2007, 7:36.

One open-label study used a multiple baseline design, in which symptoms are assessed several
times before and after treatment (this is more rigorous than typical open-label designs). The study
involved 16 children with ASD who received 40 HBOT sessions (1.3 atm, 24% oxygen) over
approximately 56 days. There was no improvement in any symptoms, as measured by behavioral
analysts directly observing the children.

Jepson 8, et al., Controlled evaluation ofthe effects ofhyperbaric oxygen therapy on the behavior of
16 children with autism spectrum disorders. J Autism Dev Disord2011, 41(5):575-588.

Randomized, Double-blind, placebo-controlled treatment studies:
One randomized, double-blind, placebo-controlled study followed 62 children undergoing 40
treatment sessions (1.3 atm, 24% oxygen, 10 sessions/week). 55 participants completed the
study, which was conducted at multiple sites. Compared to the placebo group, the treatment group
had significantly greater improvements on the Clinical Global Impressions (CGI) scale rated by the
clinicians. For the parent evaluations, the treatment group had slightly more improvements on the

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