This study examined whether the family history method can be used to
detect cases of schizophrenia-related personality disorder in the families
of schizophrenic patients. After proposing specific family history criteria
for this diagnosis, the authors applied these criteria in a blind family
history study and found that schizophrenia-related personality disorders
were significantly more common in the first- degree relatives of
schizophrenic patients than in the relatives of medically ill controls.