In a report from the National Council for Special Education (1), there are approximately 6,026 people aged 0-18 years with an autism spectrum disorder. This is based on a prevalence of 0.2% for autistic disorder and a prevalence of 0.36% for Asperger syndrome – a combined prevalence of 0.56% (or 1 in 178 children). This estimate would further imply a total of 26,000 people at all ages (0.56% of the population of 4.6 million in Ireland).
A recent estimate from the Centers for Disease Control (2) in the US gave a prevalence of 1.13% (or 1 in 88 children) who were professionally evaluated as having an autism spectrum disorder. This would equate to 52,000 people at all ages in the Irish population.
The most recent report from the CDC (3) gives a parent-reported prevalence of 2% (or 1 in 50), which would translate to 92,000 people in Ireland if the same prevalence applied at all ages within the Irish population.
The true prevalence in Ireland is unknown, but it seems reasonable to assume that the number of people with autism lies somewhere between 26,000 and 92,000 people, and probably around the middle estimate of around 52,000 people at all ages in Ireland. Of these, the number of children would be between 6,700 and 24,000, with a mid-point estimate of 13,600. (There were 4.6 million people in Ireland in 2012 (4), 1.2 million under 18 and 3.4 million over 18).
1. NCSE International Review of the Literature of Evidence of Best Practice Provision in the Education of Persons with Autistic Spectrum Disorders. Autism Centre for Education and Research, University of Birmingham. Principal Investigators, Dr. Sarah Parsons and Dr. Karen Guldberg.
3. CDC Changes in Prevalence of Parent-reported Autism Spectrum Disorder in School-aged U.S. Children: 2007 to 2011–2012 by Stephen J. Blumberg, Matthew D. Bramlett, Michael D. Kogan, Laura A. Schieve, Jessica R. Jones, and Michael C. Lu.
4. CSO Population and Migration Estimates April 2012 (with revisions from April 2007 to April 2011)