A massive and co-ordinated research effort to identify the causes of autism is urgently needed, say the authors of a major UK Medical Research Council review of autism research.
The review concludes that autism and related disorders are far more common than previously thought – and that there is no firm evidence to date linking any environmental trigger with the disease.
Autism and related disorders affect six in every 1000 children aged under eight, the team found. The previous figure accepted by the MRC was between one and two per 1000. The increase is down to altered ideas about what constitutes an “autism spectrum disorder”, as well as increased awareness of the condition, the group says.
Their review of previous research revealed no evidence of a link between the controversial MMR vaccine and autism. The group also found no firm evidence linking immunological or bowel problems with the disorder – links that have been suggested by some researchers.
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“There have been some recent very high quality epidemiological studies in the UK, but individually, these studies are quite small. We need future research that is interdisciplinary and has the strength of being population-based, so we’re not studying biased samples of children,” says Carol Dezateux, a consultant paediatrician at the Great Ormond Street Hospital in London, and a member of the review group.
Nature vs nurture
Judith Barnard of the UK’s National Autistic Society, who took part in the review, says: “We’re very pleased with this report, which has been long overdue. It’s an area that has been woefully under-researched in the UK in the past. Most importantly for me, the report formally recognises that autism can no longer be considered to be a rare condition.”
The group says it is increasingly clear that there is a genetic component to autism. But long-term prospective studies of large numbers of children, including genetic, as well as detailed health and lifestyle data, will be needed to help tease apart the genetic and environmental components of the disorder, says Dezateux.
Much more basic biological work, to investigate differences between autistic and healthy brains, for example, is also necessary, she says.
Dedicated funding
How that research will be co-ordinated is another matter. The MRC can boost “robust” inter-disciplinary autism research proposals by targeting funds at these projects, Dezateux says.
But, says Barnard: “Two years ago, the MRC issued a report on autism and bowel disorders and called for specific research. Nothing on that list has yet been done, because they are waiting for ‘robust’ proposals.”
“We are asking the Department of Health for a dedicated funding stream for autism research,” she says, “and raising the issue of a need for a pro-active body to implement the findings of these review.”
The review is published on the MRC’s website.
