Brief report: Hyperbaric oxygen therapy (HBOT) in children with autism spectrum disorder: a clinical trial.

Gallagher et al. (2012) gave ten children with autism 40 one-hour dives in a hyperbaric oxygen chamber. Each dive pumped pure oxygen at higher-than-normal pressure. Parents and clinicians filled out behavior checklists before and after the series.

The team also drew blood to look for oxidative-stress markers. They had no control group, so every child got the real treatment.

Moms, dads, and clinicians noticed small gains in irritability and social behavior. The lab numbers did not change; oxidative markers stayed the same.

Because there was no comparison group, the authors could not say the chamber caused the mild improvements.

Laposa et al. (2017) ran a similar before-and-after study with zero treatment. Caregivers still reported big gains on the same checklists. This shows that parent-rated "improvement" can appear without any real intervention, matching the weak HBOT results.

Ramírez-Guerrero et al. (2025) reviewed all antioxidant-style therapies for autism. They found mixed, tiny effects and warned against using any pill or chamber as stand-alone care. Their verdict lines up with the small, shaky HBOT outcome.

Christian et al. (1997) tested high-dose vitamin B6 and magnesium in a real RCT. That trial found no benefit, while the 2012 HBOT study claimed mild gains. The difference: the vitamin study had a placebo group, making its null result more trustworthy.

Families may ask you about hyperbaric chambers. You can explain that parent scores alone are not enough; without a control group we cannot credit the oxygen. Keep your focus on behavior-analytic strategies that already have strong evidence. If a client is using HBOT, track target behaviors with direct observation to see if real change occurs.