Autism — a neurodevelopmental disability — has become a political issue. How did this happen?

There is a short answer, which begins with the press conference held two months ago by US President Donald Trump and his health secretary Robert F Kennedy Jr, in which they linked a rise in the prevalence of autism to increases in environmental toxins, such as women taking paracetamol during pregnancy, or the use of vaccines in early childhood. While the scientific community has dismissed these views as unsubstantiated, and pointed to evidence disproving them, the episode raised questions about why politicians should be entering into debates about the science of autism.

To understand the unlikely relationship between autism and politics, however, we must turn to the diagnosis of autism, since today this has become contentious. Before 1994, it was mostly diagnosed in people who also had an intellectual (or learning) disability, and in those who had language delays or difficulties. Clinicians back then called it classic autism, and we all referred to the paper published in 1943 by child psychiatrist Leo Kanner at Johns Hopkins University in Baltimore, and credited him with the first report of autism.