title: Epidemiology and etiology of autistic spectrum disorders difficult to determine.
abstract: The epidemiology of the autistic spectrum disorders is changing. A clear increase in prevalence has been noted during the past 2 decades. What is less clear is the cause for this increase. Multiple factors appear to be responsible. The preponderance of evidence suggests most of the rise in incidence and prevalence is related to changes in diagnostic criteria and greater awareness on the part of both professionals and parents. Proposed theories of causation, which also seek to explain the increase in prevalence, have not been substantiated. Further research is needed to better determine the incidence and prevalence of these disorders and their etiologic factors.
authors: Columbus Children's Hospital, Ohio State University, Columbus, OH, USA.
authors: Daniel L
authors: DL
authors: Coury
authors: Patricia L
authors: PL
authors: Nash
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000139:chemically induced; D001321:Autistic Disorder / Q000453:epidemiology* / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D006801:Humans; D015994:Incidence; D008607:Intellectual Disability / Q000453:epidemiology; D007805:Language Development Disorders / Q000139:chemically induced; D022542:Measles-Mumps-Rubella Vaccine / Q000009:adverse effects; D011310:Preservatives, Pharmaceutical / Q000009:adverse effects; D015995:Prevalence; D013849:Thimerosal / Q000009:adverse effects
chemical_list: D022542:Measles-Mumps-Rubella Vaccine; D011310:Preservatives, Pharmaceutical; D013849:Thimerosal