Writing in the New England Journal of Medicine, scientists from the University of California say they have new evidence that autism begins in the womb. The conclusions come from studying brain tissue from 22 children with and without autism that had died in accidents or from unrelated diseases, aged between 2 and 15 years. The scientists discovered key differences in the outer layer of the brain, called the cortex, in ten out of 11 children with autism, compared to one in 11 children without the condition.
The changes were dotted about in brain regions involved in social and emotional communication, and language, and are likely to have arisen during the second or third trimester of pregnancy. Importantly, the researchers think that their findings might explain why some toddlers with autism show signs of improvement if treated early enough, as younger brains are more likely to rewire themselves. So the race is on to find out whether these changes hold up in further studies, and how the information might be used to inform earlier identification of autistic children so appropriate interventions can be made as early as possible.