Parents of autistic children who were guided by therapists in how to communicate better with their children and practised the approach daily saw a reduction in the severity of autism symptoms, say U.K. researchers.

In the parent-mediated social communication therapy or PACT trial, parents of children aged two to four at the severe end of the autism spectrum worked with a therapist who helped the parents tune into their child's subtle communication, such as hand gestures or moving a toy.

As part of the experiment, a therapist would monitor interactions between the parent and child, watching and waiting for the child to communicate, and then help to reinforce the communication, such as with a smile.

"This isn't a cure," the study's lead author, Prof. Jonathan Green of the University of Manchester and Royal Manchester Children's Hospital, said in an interview. "The autism doesn't disappear, but it becomes substantially less severe during this period and that's sustained. That makes a real difference to the kids' lives."

For the randomized trial published in Wednesday's issue of the medical journal The Lancet, researchers studied 152 preschoolers who received 12 months of therapy sessions from their parents followed by 20 to 30 minutes per day of planned communication and play or treatment as usual.

The latest study is a followup analysis of the children about six years after the treatment ended, when the children were about 10.5 years old on average.

Devin Walters

Devin Walters was not very verbal when he was first identified as being on the autism spectrum, his mother recalls. (CBC)

Autism severity was measured using an international standard measure that combines social communication and restricted and repetitive behaviour symptoms into an overall score.

Communication between each child and a parent was videotaped and then evaluated as part of the study.

The researchers say their results are the first to show long-term improvement in symptoms after a randomized controlled trial of early intervention in autism spectrum disorder, which affects about one per cent of children and young people.

Teachers who weren't aware which group the children were in also assessed them.

Overall, the proportion of children with symptoms of high severity decreased by about 17 per cent in the treatment group compared with usual treatment, Green said.

An effective early treatment that changes the long-term course of the disorder could benefit individuals, families and society, but it's been hard to demonstrate until now.

Powerful for parents

The six years of followup is exciting, said psychologist Dr. Jessica Brian of Holland Bloorview Kids Rehabilitation Hospital in Toronto, who was not involved in the study. She's investigating a similar model to help children with autism to develop their communication skills.

It was assumed that helping young children make small gains would build over time and assist their development. These findings offer evidence that's indeed the case, Brian said.

"There's nothing more powerful for a parent than seeing their child make the gains and feeling that they contributed to that in some way," Brian said.

Jessica Brian

Therapists can give parents a 'tool box' to foster their child's development in natural ways, says autism researcher Dr. Jessica Brian. (CBC)

Another advantage is it didn't involve a lot of therapy time, which is costly to the health-care system, she said.

"We're not really teaching parents to be therapists per se. We're just almost giving them a tool box for fostering their child's development in natural ways."

The researchers did not find any group difference in language scores, such as grammar, at followup. Overall mental health problems such as anxiety also didn't change.

The followup data from the U.K. team raises the "intriguing possibility that a 12-month, relatively low-intensity intervention has the potential to produce long-term improvements in autism symptoms," education Prof. Jeff Sigafoos of Victoria University of Wellington in New Zealand said in a journal commentary published with the study.

Parents encouraged

The findings are empowering, said Sue Walters of Aurora, Ont., who has two sons on the autism spectrum. She and her husband attended classes to help their eldest, Devin, to communicate better.

"It resonated with me," Walters said of the study's results. "Parents of autistic children know that starting very early and being able to get that serious groundwork, the really rudimentary stuff, is what's going to make a change for our kids."

Future research could help identify the key components of the treatment and its underlying mechanism, Sigafoos said. Emerging evidence favouring PACT and similar programs suggests some major, yet undetermined, developmental mechanism might be involved, he said.

The study was funded by the Medical Research Council. 

Study Aims to Crack Autism Code14:37

With files from CBC's Christine Birak