Asperger syndrome is a form of autism long distinguished from more severe forms of the disorder by its lack of cognitive and language deficits1. Because of their normal to high intelligence and lack of difficulty acquiring language, people with Asperger syndrome generally receive a diagnosis in middle childhood or later.
Relevance to autism:
Individuals with Asperger syndrome share the social deficits, restricted and repetitive behaviors and interests, and impairments in theory of mind and executive function characteristic of autism2,3. New research shows little difference between individuals with high-functioning autism and Asperger's syndrome4,5,6.
As a result, Asperger syndrome will be folded into the autism spectrum in the DSM-5, the forthcoming edition of the Diagnostic and Statistical Manual of Mental Disorders, due out in 2013.
Individuals with Asperger syndrome typically have an intense interest in a few topics. They focus on these topics so intensely that they become expert in these areas. This characteristic of Asperger syndrome has given rise to the (mistaken) popular notion that all individuals with the syndrome are savants.
People with Asperger syndrome often have difficulty initiating or maintaining a reciprocal conversation, partly due to their intense focus on a few favored topics.
Studies have shown Asperger syndrome is up to ten times more common in males than females. However, this skewed gender ratio may reflect difficulties in identifying the disorder in girls and women. An emerging body of research indicates that girls with the disorder tend to be diagnosed later in life, perhaps because they are better at masking their symptoms7.
Asperger syndrome is named for Hans Asperger, an Austrian child psychologist, who published the first description of the disorder (which he called 'autistic psychopathy') in 1944. Asperger described children he called 'little professors,' who displayed an intense focus on a special interest and were unable to hold reciprocal conversations as a result.
Because Asperger wrote in German, his work did not become well-known in the English-speaking world until autism researcher Lorna Wing used the name 'Asperger syndrome' in a 1981 paper8.
Asperger syndrome was first introduced into the Diagnostic and Statistical Manual of Mental Disorders in 1994, distinguishing it from 'autistic disorder' by a lack of significant delay in language and normal cognition.
In the DSM-5, Asperger syndrome will be formally merged into the autism spectrum and will cease to exist as a separate diagnostic category.
Klin A. et al. J. Child Psychol. Psychiatry 36, 1127-1140 (1995) (1)
Senju A. et al. Science 325, 883-885 (2009) (2)
Verte S. et al. J. Autism Dev. Disord. 36, 351-372 (2006) (3)
Mayes S.D. et al. J. Abnorm. Child Psychol. 29, 263-271 (2001) (4)
Witwer A.N. and L. Lecavalier J. Autism Dev. Disord. 38, 1611-1624 (2008) (5)
Howlin P. J. Autism Dev. Disord. 33, 3-13 (2003) (6)
Kopp S. and C. Gillberg Res. Dev. Disabil. Epub before print (2011) (7)
Wing L. Psychol. Med. 11, 115-129 (1981) (8)