autism

One of a spectrum of disorders defined by problems with communication, imagination, and social interaction. The symptoms may be present from birth or may develop in early childhood, around the third year. In rare cases, autistic individuals may show extraordinary talents in some areas, for example music, arithmetics, or drawing, but most will have learning difficulties. The causes of autisim are unknown, but it is thought to involve a number of environmental and genetic factors affecting the development of the child's brain. Special education may bring about some improvement.

First described in the 1940s by the Austrian-US psychiatrist and pediatrician Leo Kanner (1894-1981) and independently by the Austrian pediatrician Hans Asperger (1906-1980), autistic spectrum disorders (ASD) were long mistaken for a psychological or even a parenting problem. They are now established to be developmental disorders of the brain that can be investigated by brain imaging studies as well as by genetic analysis of the contributing factors.

A 2001 review of the subject commissioned by the UK government concluded that 0.6% of today's children are on the autistic spectrum. Whether the incidence has in fact increased during the 20th century (either through environmental factors or through better reproductive success of people who carry some of the genetic factors), or whether the observed increase is due to improved diagnosis remains controversial.

Asperger's syndrome is a diagnosis normally reserved for individuals at the high-functioning end of the autistic spectrum. Sufferers have a lack of understanding of social situations and an inability to empathize. They tend to develop strong interests within a narrow subject area on which they may focus for long periods. Asperger's is often undiagnosed and may affect as many as 1 in 300 people, mostly males.