Choosing control groups in the study of schizophrenic subtypes

The choice of comparison groups in the study of schizophrenic subtypes is discussed. Current research rests upon the comparison of schizophrenic subtypes and controls unselected for the subtype characteristics used to divide the schizophrenics. One cannot infer, on the basis of this type of group comparison, whether subtype differences are specific to schizophrenia or reflect general personality and behavioral characteristics. It is suggested, therefore, that control groups be selected for their comparability to the schizophrenics on subtype characteristics.