Epidemiology of autistic conditions in young children

Abstract

Data concerning 32 autistic children identified in a previously reported survey of the County of Middlesex made in 1963/64 are presented, in comparison with a group of 22 non-autistic handicapped children with certain behavioural similarities. — Parents of the autistic probands were superior in socio-economic status, intelligence and education. Mothers in the autistic group were educationally and intellectually superior to those in the comparison group in all social classes. — Previous reports indicating no raised incidence of psychotic illnesses in relatives of autistic children were confirmed, but there was a greater incidence of other serious mental illness in the families of the autistic group than in the comparison group. In parents and collateral relatives of the autistic children, 3.2% had a serious mental illness, and 4.8% of siblings were markedly abnormal. Five of 32 autistic children had a mentally ill parent. — No birth-order effect was found, and maternal age was not raised. There was no excess of immature births. Complications in pregnancy and birth were infrequent; in the autistic probands fewer were found than in the comparison group, but more than in their own siblings. — The incidence of neurological and other abnormalities was less in the autistic than in the comparison group. These signs were found mainly in low grade probands with early developmental retardation. — The need for the reporting of detailed uniform data is emphasised, so that comparisons between different groups of autistic children may be more productive.