The Copenhagen High-Risk Project, 1962-86.

Since 1962 we have followed a sample of 207 children at high risk for schizophrenia as well as 104 control children. For these individuals, the following factors and their interaction are related to an increased risk for schizophrenic breakdown: (1) greater schizophrenia family backgrounds, (2) perinatal trauma, and (3) unstable parenting and public institutional child care. The perinatal difficulties are positively related to adult periventricular atrophy. Results of a subsequent study tentatively suggest that part of the neurological deviance in schizophrenia may be produced by disruption occurring in the second trimester of fetal development.