A child's ability to effectively communicate with peers, parents, and caregivers impacts their level of independence and quality of personal relationships. This retrospective study will compare the speech development of participants aged 2 - 17 years that received 40 sessions of HBOT at 2.0 ATA to those who had not. Both groups will have a verbal assessment every six months. There were 32 subjects in the HBO group and 33 subjects in the non-HBO group. The statistical analysis will focus on whether Hyperbaric Oxygen Therapy made a significant difference in Verbal Behavior Milestones Assessment and Placement Program (VB-MAPP) or Assessment of Basic Language and Learning Skills (ABLLS) results.

Methods: This was a study designed to retrospectively determine any association between hyperbaric oxygen therapy (HBOT) and change in verbal scores in children with autism spectrum disorder (ASD). All children aged 2 to 17 years, diagnosed with ASD who completed a verbal test every six months (either Verbal Behavior Milestones Assessment and Placement Program or the Assessment of Basic Language and Learning Skills), received applied behavioral analysis at Oxford Recovery Center (ORC) were screened for inclusion, some of whom had elected to receive HBOT (at least 40 sessions for 60 minutes at 2.0 ATA).

Inclusion Criteria:

• Diagnosed with autism spectrum disorder by a qualified practitioner
• Obtained medical clearance for hyperbaric oxygen therapy
• Received applied behavioral analysis at Oxford Recovery Center
• Received two of the same age appropriate verbal test 6 months apart

Exclusion Criteria:

• History of seizure disorder
• Diagnosis of genetic or mitochondrial mutation

The medical records were reviewed for children aged 2 - 17 years who were diagnosed by a qualified practitioner with autism spectrum disorder (ASD) and treated at the Oxford Recovery Center between Jan 2018 and July 2021. Each child who underwent a minimum of 40 hyperbaric oxygen treatments at 2.0 ATA in a hard sided monoplace chamber, had two age-appropriate verbal tests 6 months apart, and received applied behavioral analysis during the study period were included in the treatment group. Children who did not undergo hyperbaric oxygen therapy, received two age-appropriate verbal tests 6 months apart, and received applied behavioral analysis were included in the control group. Any child diagnosed with seizure disorder, genetic or mitochondrial mutation were excluded from the study cohort.