According to study author Christine Ecker in today’s Guardian:
We know already that people with autism have differences in brain anatomy and some regions are just bigger and smaller or just different in shape…[o]ur technique can use this information to identify someone with autism.
The study used 20 non-autistic controls and 20 autistic people – all adults – and found "significant differences" in the grey matter areas of the brain which control behaviour and language. This is nothing new in itself, differences in brain structure have long been known about in regards to autism. What's new in this study is the method – and resultant accuracy – of the detection of autism.
In the experiment, Ecker showed that her imaging technique was able to detect which people in her group had autism, with 90% accuracy. “If we get a new case, we will also hopefully be 90% accurate,” she said. The research, supported by the Medical Research Council, Wellcome Trust and National Institute for Health Research, is published today in the Journal of Neuroscience.
If this is established as a viable method (Carol Povey of NAS states that further testing is still required) then it’ll be the first true objective test for autism ever developed. So far, as everyone knows, autism is diagnosed based on the opinion of a clinician (or team of specialists). Whilst they will probably still play a role, this test offers an objectivity that would be unparalleled. It would also have the interesting effect of making the DSM diagnosis largely obsolete.