Autism spectrum disorders--are they really epidemic?

Abstract

Aim: The aim of this paper is to report on how different external methodological factors influence estimates of ASD prevalence.

Methods: PubMed searches was conducted using the search terms, "Autism", "Autistic Disorder", "Autism Spectrum Disorders", "Asperger", "Prevalence" and "epidemiology", in combination. In total 49 studies were included. We also performed a manual search for and reviewed related articles referenced in the original articles.

Results: The reported prevalence rates of ASD vary widely, and so do the methodology used in the studies.

Conclusion: There are reasons to argue that the methods used in some studies cause the high prevalence rates reported recently.