I also think there is probably not a single cause for either ASD or ADHD -- there is probably both a genetic component and an environmental component involved.

I also think there is probably not a single cause for either ASD or ADHD -- there is probably both a genetic component and an environmental component involved. At the same time, it's very hard to tease these things apart, especially with whether the microbiome plays a role because that too is significantly hereditary.