Health secretary Robert F. Kennedy Jr. says a "massive testing and research effort" will focus on the cause of autism, but his approach has raised alarms.

US Health Secretary Robert F Kennedy Jr has pledged "a massive testing and research effort" to determine the cause of autism in five months. Experts cautioned that finding the causes of autism spectrum disorder – a complex syndrome that has been studied for decades – will not be straightforward, and called the effort misguided and unrealistic.