[ac29]

> "By the time the children were an average of 8.9 years, 25.8% had been diagnosed with ADHD only, 6.6% with ASD only and 4.2% with ADHD and ASD"

This seems very high - I'd call in to question the validity of the diagnosis (these diagnoses are obviously somewhat subjective). Given that those numbers are for the total cohort, that suggests that something like a full half of the upper third of children were diagnosed with ADHD.

[Engineering-MD]

I agree, this is not representative of the normal population and calls the results into question.