Autism, then, is more common than Down syndrome, childhood cancer, or Fragile X syndrome. As a result of the NIH conference, screening for autism will be included in research being conducted by a national network of epidemiologic sites studying childhood disorders. However, these problems are not consistent across cases of autism nor specific only to autism. These problems do not appear to cause autism, but may be reflections that fetal or neonatal development was compromised in some way. These regions include the amygdala, hippocampus, septum, mammillary bodies, and the cerebellum.
Autistic brains are slightly larger and heavier.
Differences have been observed in terms of size and in the number and size of certain cells within the central nervous system in autism. Which differences are unique to autism remains to be demonstrated. Combining neuropsychologic techniques with structural and functional imaging will provide powerful tools for understanding these deficits and strengths. In these studies, standardized procedures are needed for diagnosis, composition of comparison groups, imaging, psychological testing, and interpretation of results. Eventually this will lead to the design of effective pharmacological treatments for the core symptoms of autism.