Autism is a pervasive brain developmental disorder that severely impacts socialization, communication, and can even cause obsessive or repetitive behavior. Autism delays normal brain development and is also related to a milder form of the syndrome known as pervasive developmental disorder not otherwise specified (PDD-N OS). Since it was first identified in 1943, there has been an increase in the rate of new diagnoses every year. Muhle, Trenracoste, and Rapin (2004) found that the rate of autism diagnoses increased 556% between the years 1991 and 1997. Many believe this increase is due to a shift in diagnostic criteria or new defining characteristics of the syndrome. . The expansion of diagnostic criteria is also indirectly linked to the increase in services provided to autistic children, thus increasing displacement. Due to this increase in diagnoses, greater awareness has been brought among pediatricians, further increasing the rate of autism diagnoses (“Autism,” 2010). Glasson et al. (2004) found that the frequency with which the disorder is diagnosed has risen to nearly 60 per 10,000 people. Another factor in the increase in autism diagnoses is that children are being diagnosed at much earlier ages. Parents identify problem behaviors earlier in the child's life, sometimes as early as 8 months of age (Bristol-Power & Spinella 1999). Studies have shown that autism is more prevalent in males than females, with a male to female ratio of 3:1 (Muhle et al., 2004). It's unclear why exactly autism tends to develop in males rather than females, but the fact that males are statistically more likely to develop autism suggests that genes associated with the article... ....nt sometimes significantly improves the child's behavioral skills. Works CitedAutism. (n.d.). Retrieved from: http://www.nlm.nih.gov/medlineplus/ency/article/001526.htmBaron-Cohen, S., Ring, H.A., Bullmore, E.T., Wheelwright, S., Ashwin, C., Williams, SCR (2000). The amygdala theory of autism. Neuroscience and Biobehavioral Reviews 24, 355-64Bristol-Power, M. & Spinella,G (1999). Research on screening and diagnosis in autism: a work in progress [Abstract]. Journal of Autism & Developmental Disorders 29, 435Glasson, E., Bower, C., Petterson, B., Klerk, N., Chaney, G., Hallmayer, F. (2004). Perinatal factors and the development of autism: a population-based study. Arch Gen Psychiatry 61,618-27Muhle, R., Tentacoste, SV., Rapin, I. (2004). The genetics of autism [Absract]. Pediatrics 5, 472-86National Institute of Child Health and Human Development (2005).