This week saw publication of a PLOS One paper on a potential environmental cause of autism that caught the attention of the media. The Daily Mail, a newspaper that has a track record of sensationalist health scares announced “Autism ‘could be triggered by very low doses of anti-depressants or other chemicals found in water supply’”. On the same day, three excellent critiques of the study appeared on the blogosphere, by Tom Chivers, writing in the Daily Telegraph, by Dianthus Medical, and by Neuroskeptic.
As it happened, I had blogged about autism earlier this week, reconsidering the enduring question of whether there really is an autism epidemic in need of explanation. I was therefore interested to see that the PLOS One paper confidently asserted: “Idiopathic ASD, caused by genetic susceptibility factors interacting with unknown environmental triggers has increased dramatically in the past 25 years.” Well, everyone agrees there has been a remarkable increase in autism diagnosis across the world in the past 25 years, but in my blogpost, I questioned whether this meant an increase in autism. So here are the arguments that I put forward that might give one pause.