Fact sheet on incidence of Asperger's syndrome, an Autism Spectrum Disorder


Prevalence estimates vary enormously. A 2003 review of epidemiological studies found prevalence rates ranging from 0.03 to 4.84 per 1,000, with the ratio of autism to Asperger syndrome averaging 5:1;[64] combining this with a conservative prevalence estimate for autism of 1.3 per 1,000 suggests indirectly that the prevalence of Aspergers syndrome might be around 0.26 per 1,000.[65] Part of the variance in estimates arises from differences in diagnostic criteria. For example, a relatively small 2007 study of 5,484 eight-year-old children in Finland found 2.9 children per 1,000 met the ICD-10 criteria for an Aspergers syndrome diagnosis , 2.7 per 1,000 for Gillberg and Gillberg criteria, 2.5 for DSM-IV, 1.6 for Szatmari et al., and 4.3 per 1,000 for the union of the four criteria. Boys seem to be at higher risk for Aspergers syndrome than girls; estimates of the sex ratio range from 1.6:1 to 4:1, using the Gillberg and Gillberg criteria.[66]


Anxiety and depression are the most common other conditions seen at the same time; comorbidity of these in persons with Aspergers syndrome is estimated at 65%.[1] Depression is common in adolescents and adults; children are likely to present with ADHD.[67] Reports have associated Aspergers syndrome with medical conditions such as aminoaciduria and ligamentous laxity, but these have been case reports or small studies and no factors have been associated with Aspergers syndrome across studies.[1] One study of males with Aspergers syndrome found an increased rate of epilepsy and a high rate (51%) of nonverbal learning disability.[68] Aspergers syndrome is associated with tics, Tourette syndrome, and bipolar disorder, and the repetitive behaviors of Aspergers syndrome have many similarities with the symptoms of obsessive compulsive disorder and obsessive-compulsive personality disorder.[69]


More males diagnosed with Asperger's than females

Like other Autism Spectrum Disorders, Aspergers syndrome prevalence estimates for males are higher than for females, but some clinicians believe that this may not reflect the actual incidence rates. Tony Attwood suggests that females learn to better compensate for their impairments due to gender differences in the handling of socialization. The Ehlers and Gillberg study found a 4:1 male to female ratio in subjects meeting Gillberg’s criteria for Aspergers syndrome, but a lower 2.3:1 ratio when suspected or borderline cases were included.



1. McPartland J, Klin A (2006). "Asperger's syndrome". Adolesc Med Clin 17 (3): 771–88. doi:10.1016/j.admecli.2006.06.010. PMID 17030291.
60. Coplan J, Jawad AF (2005). "Modeling clinical outcome of children with autism spectrum disorders". Pediatrics 116 (1): 117–22. doi:10.1542/peds.2004-1118. PMID 15995041. Lay summary – press release (2005-07-05).
61.Chiang HM, Lin YH (2007). "Mathematical ability of students with Asperger syndrome and high-functioning autism". Autism 11 (6): 547–56. doi:10.1177/1362361307083259. PMID 17947290.
62. Herera S. "Mild autism has 'selective advantages'", CNBC, 2005-02-25. Retrieved on 2007-11-14.
63. Moran M (2006). "Asperger's may be answer to diagnostic mysteries". Psychiatr News 41 (19): 21.
64. Fombonne E, Tidmarsh L (2003). "Epidemiologic data on Asperger disorder". Child Adolesc Psychiatr Clin N Am 12 (1): 15–21. PMID 12512396.
65. Fombonne E (2007). "Epidemiological surveys of pervasive developmental disorders", in Volkmar FR: Autism and Pervasive Developmental Disorders, 2nd ed, Cambridge University Press, 33–68. ISBN 0521549574.
66. Mattila ML, Kielinen M, Jussila K et al. (2007). "An epidemiological and diagnostic study of Asperger syndrome according to four sets of diagnostic criteria". J Am Acad Child Adolesc Psychiatry 46 (5): 636–46. doi:10.1097/chi.0b013e318033ff42. PMID 17450055.
67. Ghaziuddin M, Weidmer-Mikhail E, Ghaziuddin N (1998). "Comorbidity of Asperger syndrome: a preliminary report". J Intellect Disabil Res 42 (4): 279–83. PMID 9786442.
68. ^ Cederlund M, Gillberg C (2004). "One hundred males with Asperger syndrome: a clinical study of background and associated factors". Dev Med Child Neurol 46 (10): 652–60. doi:10.1111/j.1469-8749.2004.tb00977.x. PMID 15473168.
69. Gillberg C, Billstedt E (2000). "Autism and Asperger syndrome: coexistence with other clinical disorders". Acta Psychiatr Scand 102 (5): 321–30. doi:10.1034/j.1600-0447.2000.102005321.x. PMID 11098802.

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The prevalence of Aspergers syndrome is not well established  but conservative estimates indicate that two to three of every 10,000 children have the condition