THE BIOLOGY OF AUTISM

Autism is a behavioural syndrome characterized by qualitative impairments in reciprocal social interaction and communication; the presence of restricted, repetitive and stereotyped patterns of behaviour, interests and activities; and, abnormal development before 36 months of age (ICD 10) (WHO, 1991). The children described by Kanner (1943) were said to be of normal intelligence, and for many years the syndrome was thought to be psychogenic. However, the finding that three-quarters of sufferers are mentally handicapped and a quarter develop epilepsy (Lockyer & Rutter, 1969; Rutter, 1970), suggested that the syndrome had a biological basis. Steady progress has been made in clarifying the role of aetiological factors and specifying the psychological deficits, whereas identification of the underlying neurobiological abnormalities has been less successful.