> Also, since I believe it's now actually agreed upon that autism rates actually ARE increasing, and not just increased diagnoses, is there any candidate theory

> Also, since I believe it's now actually agreed upon that autism rates actually ARE increasing, and not just increased diagnoses, is there any candidate theory as to why mutations would be higher in developed countries recently? This paper is mostly about the impact of de-novo mutations, i.e mutations that are found only in the child and not in its parents. One theory is that as paternal age is rising and a higher paternal age is linked to a higher number of de-novo mutations which leads to a higher chance of de-novo mutation related genetic diseases like in this case autism (and other mental disorders). Note that the paternal age in developed countries has been at a historic low in the mid 20th century, which may have lead to a historically low rate of mental disorders in the last decades.