Ever since reading West Hunter I've been intrigued by the idea of mutational load as an explanation for increasing prevalence of mental disorders. It would mean chance of having these disorders would increase with increasing paternal age, and in fact that's what we find. Since everyone's waiting longer to have babies nowadays, that explains some of the change.

I wonder if increasing paternal age explains even more of the change than that article lets on, just because it's accumulating over generations; it's not just that your dad was older, it's that your grandfather was older and therefore your father started with more mutations and so on. You can't measure that effect just by separating people into autistic and neurotypical and then asking them how old their fathers were.