A new study suggests children with autism may benefit from hyperbaric oxygen therapy. But not everyone agrees it's time to recommend the costly potential treatment.

The study, published in BMC Pediatrics, was a small one, involving just 62 children with autism and lasting just four weeks. It found that the children who regularly used hyperbaric therapy saw improvements in their language and social interaction abilities.

Hyperbaric therapy involves inhaling oxygen at a pressure greater than 1 atmosphere (atm) in a pressurized chamber.

In this study, the children, aged between two and seven years old, were randomly assigned to either 40 hours of treatment in a hyperbaric chamber at 1.3 atm and 24 per cent oxygen (treatment group) or slightly pressurized room air at 1.03 atm and 21 per cent oxygen (non-treatment group).

Their outcomes were evaluated by three scales: the Clinical Global Impression (CGI) scale, the Aberrant Behavior Checklist (ABC), and the Autism Treatment Evaluation Checklist (ATEC).

The study found that children with autism in the treatment group had significant improvements in overall functioning, receptive language, social interaction, eye contact, and sensory/cognitive awareness compared to children in the non-treatment group.

In all, 30 per cent in the treatment group were rated by doctors as "very much improved" or "much improved" compared with eight per cent of those in the control group. Eighty per cent in the treatment group improved compared with 38 per cent of controls.

The study, led by Dr. Dan Rossignol from the International Child Development Resource Centre in Florida, was not able to measure whether the results were long-lasting or permanent.

While the evidence is still preliminary, some parents in Canada are already turning to this therapy.

Five days a week, Lara Linhares and her eight-year-old son Quin climb into a hyperbaric chamber together at a clinic called Under Pressure in Port Credit Ont. for an hour.

Linhares says the oxygen therapy appears to be working, making her son more approachable.

"After our first session, he came up and hugged me, unprompted. Speaking as a mom of a child with autism, you can't put a price on that," she says.

"He has been using more language, putting more words together, forming longer sentences since we started."

The hyperbaric chamber allows patients to breathe in much higher levels of pure oxygen, in the hope that it will increase blood flow.

The therapy is typically used to heal wounds, but some clinics say it is beneficial for children with fetal alcohol syndrome and cerebral palsy. Now, some are also promoting its use for autism.

"It's simple, it's effective and it's safe," says certified hyperbaric technologist William Eddy. "We're getting oxygen deeper into the brain."

Margaret Spoelstra, the executive director of Autism Ontario, notes that this is just the first randomized controlled study on the therapy's use in autism and the results need to be replicated in larger studies.

"It seems encouraging to parents, but I worry about parents' response to this. This is still a small sample. More children need to be studied to draw conclusions," she says.

She points out that the children in the study's placebo group also showed improvements. And the effects of hyperbaric therapy need to be evaluated over the medium and long term, she says.

While there are more studies under way, Spoelstra worries parents will sign up for treatments that cost $300 an hour without convincing proof.

"I'm worried that parents might rush to say, 'This is something we need for our children'," she says.

"This therapy costs a lot of money for which the evidence doesn't exist enough to warrant it being a recommended treatment."

Linhares says she's not going to wait years for further studies.

"Let our kids be the guinea pigs of this. We're willing to take that chance that it will benefit them," she says.

For those parents of autistic children who want to try the treatment, Spoelstra recommends they check the reputability of any clinic, because there are some risks involved with hyperbaric chambers and not everyone is qualified to operate them.

Linhares says she's weighed the costs and is preparing to spend $6,000 for 20 treatments for her son Quin. She says she's paid back with hugs.

With a report by CTV's medical specialist Avis Favaro and producer Elizabeth St. Philip