Reasons for the Rise in Incidence
Broadening of the definition
-In 1989, the new DSM was published. The DSM-III required 6 of 6 characteristics to be displayed, the DSM-IV required 6 of 16.
-In 1995, autism disorder was grouped together with 4 more subtypes into a broader spectrum disorder.
-Groups like AutismSpeaks, Autism Society of America, and National Autism Association
-Media publicity at the end of the 1990s when autism was linked to the childhood vaccinations
Progressed medical knowledge
-New diagnostic interviews: ADI-R (published in 2003 by Western Psychological Services (WPS)), ADOS (commercially available in 2001, also from WPS), etc. For more information on the different types of interviews, click here.
-Training courses were organized for professionals, which spread knowledge
Development of specialist services, and government funding
-In 1991, autism was included in the Individuals with Disabilities Education Act
-Doctors may diagnose a child with autism who may just have a language disorder, in order to get them the government funding for speech therapy, and other services.
Autism prevalence by year. Based on census by the US Public school systems on individuals ages 3-22 receiving special education services up to December of the 1995 school year. (Graphic courtesy of Thoughtful House Center for Children, Graphing IDEA Professional 2010, Thoughtful House, Austin, TX. Accessed at http://www.thoughtfulhouse.org/disabilities/ on October 6, 2010.)