Imagine you wake up one day and all the familiar signals of human communication are unintelligible. A smile no longer expresses mirth or happiness, a raised voice no longer reflects excitement or anger. You can exchange words with other people, but you're talking through a heavy curtain of uncertainty. You find it difficult or impossible to behave the way people seem to expect. Welcome to the baffling world of autism, a range of disorders that is affecting a growing number of people and continues to perplex scientists searching for causes and cures.
The degree to which autism is on the rise is a matter of some controversy. There's no doubt that the number of children identified as having an autism-related disorder (often described as being on the autism spectrum) has surged in the past decade or so. What's not so clear is whether this represents a true increase in prevalence or just greater awareness of the condition (page S2). Indeed, our understanding of the disorder is evolving — and the shifting definition could deny some children access to the educational and social services that give them a better chance to succeed (S12).
This Outlook is an editorial collaboration between Nature and SFARI.org, the news website of the Simons Foundation Autism Research Initiative. SFARI.org operates with editorial independence from the Simons Foundation and did not participate in the editing or commissioning of articles about research funded by the Simons Foundation.
We find that uncertainty still shrouds much of autism. Genetic analysis is beginning to yield candidate genes and some of the underlying physiology of autism (S4). Yet, there are very few treatments available (S14). And little is known about what happens when children with autism grow up (S10).
We acknowledge the financial support of the Nancy Lurie Marks Family Foundation, the Simons Foundation, Roche, Autism Speaks and The Autism Science Foundation. As always, Nature retains responsibility for all editorial content.