This new form of therapy is said to offer a “potential breakthrough” in care for millions of families.
Parents were given intense communication training to teach them ways to interact with their children with autism, as part of a long-term study published in The Lancet.
Six years later the therapy was shown to have “moderated” the behaviour of children with severe autism symptoms.
“The advantage of this approach over a direct therapist-child intervention is that it has potential to affect the everyday life of the child,” said Professor Jonathan Green at the University of Manchester who lead the study, according to The Guardian.
“Our findings are encouraging, as they represent an improvement in the core symptoms of autism previously thought very resistant to change.”
The trial involved 152 children with autism in Manchester, who were aged two to four. The families of the children visited a trial centre twice a week for six months.
Parents were trained by communication specialists to be able to highlight and respond to “easily-missed” moments when a children with autism subtly tried to communicate. They were also shown how to get the most out of these moments.
The families were filmed while in a room with a box of toys. When a child offered a toy or made a noise, the parent was encouraged to respond. When a child said a word, the parent was asked to repeat it and add something else. They were then asked to repeat this practice at home.
By picking up on these moments of communication, parents slowly enabled their child to speak more.
The families who had the therapy were compared to a control group of families who were given the usual therapies for children with autism.
From those who were given usual therapies, the 50% who had severe autism at the beginning increased to 63% six years later.
For those who had the intense communication training, the 55% of children who had severe autism decreased to 46% six years later.
“This is not a ‘cure’, in the sense that the children who demonstrated improvements will still show remaining symptoms to a variable extent,” added Professor Green.
“But it does suggest that working with parents to interact with their children in this way can lead to improvements in symptoms over the long term.”
Commenting on the study, Dr Judith Brown, head of autism knowledge at the National Autistic Society, told The Huffington Post UK: “This study is the first to find a sustained improvement of this kind.
“We welcome these results at the National Autistic Society, which show the positive impact of parents’ early involvement in their children’s therapy.
“Families are often on a steep learning curve after diagnosis about how to best support their autistic children. This study confirms our view that parents must be helped to understand their child’s autism so they can be properly involved in decisions and in support and intervention for their child.
“Professor Jonathan Green has also put improving the everyday lives of autistic children and their families at the centre of his study. We hope to see more research with this same focus, which promises to improve the way clinicians work with families and, ultimately, improve life for thousands of autistic children.”