Psychiatric problems were assessed in two groups of adoptees by interviewing the adopting parents. One group of 59 adoptees, the ‘experimental’, were born of psychiatrically disturbed biological parents; the other group, the ‘control’ of 54 adoptees, had psychiatrically ‘normal’ biological parents. Both groups had been separated from biological parents at birth.
The incidence of psychiatric conditions requiring professional care was significantly higher in the experimentais than in the controls (37 per cent vs. 14 per cent). In the experimental group more males than females were disturbed (59 per cent vs. 30 per cent). Most of the excess of disordered males were diagnosed hyperactive. There was some evidence of correlation of the type of psychiatric diagnosis of the biological parent with that of the adoptee.