I have heard many observations that vaccines are increasing the ADHD and autism rates.
Another aspect that bothers me is that the definition of autism has changed dramatically.
In the 1980'ies, autism and introversion had very different meaning and there wasn't much overlap.
Nowadays, if you answer on an autism test that you are not very interested in going to parties - which is a typical introvert position - you are automatically placed on the autism spectrum.
When the definition is diluted, everyone is classified within the definition.