Children were given 80 1 hour sessions in a Vitaeris 320 inflatable chamber (a model used commonly in HBOT treatment). 6-10 sessions/week were performed. Children were split into two groups matched by age and number of ABA hours already received. Parameters like supplement use and diets remained unchanged during the time of the study. For the treatment group the chambers were inflated to 1.3 atm, with enriched oxygen air (24-28% O2, compared to 21% for regular air).
The children were given multiple assessments:
All assessments were conducted by trained assessors who were blind to group assignment. To maximize the study’s ability to detect change in any symptom area relevant to autism, a large variety of assessments were used, including the following: the ABC (Aman & Singh, 1994), ADOS (Lord et al., 1999), Behavior Rating Inventory of Executive Functioning (BRIEF; Gioia, Isquith, Guy, & Kenworthy, 2000), Clinical Global Impression Scale (CGI; Guy, 1976), Parent Stress Index (PSI; Abidin, 1995), Peabody Picture Vocabulary Test (PPVT-III; Dunn & Dunn, 1997), Repetitive Behavior Scale (RBS; Bodfish, Symons, & Lewis, 1999), SRS, Vineland Adaptive Behavior Scales—Second Edition (VABS-II; Sparrow, Cicchetti, & Balla, 2005), and the Beery-Buktenica Developmental Test of Visual-Motor Integration—5th edition (VMI-5; Berry and Berry, 2004 K.E. Berry and N.A. Berry, The Berry-Buktenica developmental test of visual-motor integration: Administration, score, and teaching manual, NCS Pearson, Minneapolis, MN (2004).Berry & Berry, 2004). The ADOS, BRIEF, PPVT -III, SRS, VABS, and VMI -5 were administered pre and post-treatment. The ABC, CGI, and RBS were administered weekly. The PSI was administered four times, once at baseline, twice during treatment, and once at completion.
The study was relatively small, with 46 participants.
Forty six participants began the study and 12 withdrew, resulting in 18 previous HBOT participants and 16 placebo participants completing all 80 sessions and follow-up measures. The primary reason reported for withdrawal was the travel required to the clinic. One participant in the placebo group withdrew after having a seizure for the first time. Mean participant age was 6.18 (previous HBOT 6.11; placebo 6.25) and mean number of ABA treatment hours per month was 109 (previous HBOT 114.7; placebo 103.3).
I won’t go into details about the specific outcomes, but the conclusion was pretty straightforward: HBOT had no effect.
No significant differences between the previous tHBOT and placebo groups were found on any of the outcome measures. Thus, the results of this study indicate that previous HBOT delivering 24% oxygen at 1.3 atm did not produce a therapeutic effect for the children who participated in our study. Therefore, previous HBOT at this dose is not recommended for the treatment of ASD symptoms.
I found it interesting how they referred to a previous HBOT study by Rossignal (another prominent member of the autism alternative medical community):
The results of this study corroborate the findings of the only other published study on previous termHBOTnext term which included a control group (Rossignol et al., 2009 D.A. Rossignol, L.W. Rossignol, S. Smith, C. Schneider, S. Logerquist and A. Usman et al., Hyperbaric treatment for children with autism: a multicenter, randomized, double-blind, controlled trial, BMC Pediatrics 9 (2009) 10.1186/1471-2431-9-21.Rossignol et al., 2009)—albeit, not the study authors’ interpretations of their findings. In both the Rossignol et al. (2009) study and the current study, both treatment and control groups improved over time, but the difference in improvement between groups appeared insignificant. In addition, the current study employed dependent measures which were far more comprehensive than in previous research on previous HBOT for ASDs, thereby increasing the probability that a therapeutic effect would have been detected if indeed one had been present.
Yes, the current study is consistent with the Rossignol group’s results, just not their interpretation.
Will this mean the end of HBOT treatments for Autism? I sincerely doubt it. Take a look at Dr. Bradstreet’s website (Dr. Bradstreet being one of the coauthors of the current study showing no effect). The first page of the site still links to the older study by Dr. Rossignol’s group (claiming that HBOT is effective) and not his own study (which shows HBOT to be not effective).
Of course, it is all the more complicated since Dr. Rossignol is also one of the ICDRC doctors. The alternative-medical community is a pretty small pond, isn’t it?
Back to the question: will this mean the end of HBOT in autism? I wish I could make bets this safe. Of course not. No alternative therapy is abandoned. As shown above, one of the authors of this study showing that HBOT is not effective for treating autism and he hasn’t stopped.