A method for testing differences in morbidity risk for affective psychoses

A modified method for testing differences between two proportions is described and its use for testing differences in the morbidity risk for affective psychoses is discussed. The method is based upon the u test for comparisonof two proportions. An example of the application of the method to study sex differences in morbidity risk for affective psychoses in parents of probands with unipolar depression and manic-depressive psychosis presented.