Some doctors suspect a link between autism and toxins in the environment. The doctors are in Montreal for a medical conference on autism.

Autism is a behavioral disorder with many facets. Children with severe cases seem to be almost disconnected, and living in their own world.

What causes autism is still a mystery. Some are born with it, some children become autistic at the age of 18 months. Researchers say those kids had a genetic predisposition to the disorder, that may be have been triggered by toxins in the environment, or toxins in the regular immunization shots that babies get.

"That's what I'm looking at now, at whether there is some immune compromise, and are there are things we can do," says Doctor Kenneth Bock.

He's not suggesting we stop vaccinating children, but rather to not give multiple vaccines at once. He also suggests giving nutritional supplements like Vitamin A in the correct doses.

Pediatrician Doctor Mary Megson agrees Vitamin A plus a dose of gastrointestinal medication can work wonders in some autistic children this pediatrician. She says, "In approximately one out of eight children that I treat that way, fifteen minutes after the first dose they wake up, talk, look at me, have a sense of humour, and talk back to their parents, act normal for their age."

Still, the experts do not expect to discover any one treatment that works for all children, or to replace the physical and mental therapies that schools for the autistic now offer.