In the first of a series of papers on a five to fifteen year follow-up, a group of children with infantile psychosis is described. The group consisted of the 63 children who were all those who attended the Maudsley Hospital between 1950 to 1958 inclusive, who were seen before the onset of any signs of pubescence and for whom an unequivocal diagnosis of child psychosis, schizophrenic syndrome of childhood, infantile autism or any synonyms of these had been agreed by all consultant psychiatrists at the Maudsley Hospital who had seen the child. The group is compared with a group of non-psychotic children who attended the same hospital at the same time, and who were individually matched for age, sex, and IQ.
There was a marked preponderance of boys among the psychotic children (4.25:1). In most cases psychotic development had been evident in early infancy with no preceding period of normal development, but in a fifth of the cases where was a fairly convincing history of two to three years normal development before there were any signs of psychosis. The chief distinguishing behavioural features were autistic relationships with people, marked retardation of speech, a lack of response to auditory stimuli, pronominal reversal and echolalia when speech developed, various ritualistic and compulsive phenomena (frequently including a striking resistance to change), stereotyped repetitive mannerisms, short attention span on given tasks together with non-distractibility, and a tendency to self-injury. Extreme variability in intellectual functioning was also quite common. There was a significant excess of children from professional backgrounds, an excess of first-born children in two-child families, and not many "broken homes'. Although several of the parents had had psychiatric treatment, none had been or were psychotic. At most, the rate of psychosis in the sibs was 2.4 per cent., but none of the sibs had a fully developed psychotic disorder. None of the children showed unequivocal abnormalities on a neurological examination when they first attended the hospital, but in a quarter evidence obtained during the follow-up period suggested the probability of some form of brain injury. Although the range of intelligence among the children was very great, the differences in intellect were associated with few differences in behavioural characteristics. It is concluded that the children are closely similar to those with infantile autism described by Kanner (1943).