A matched-paired comparison of treated versus untreated schizophrenia spectrum cases. A high-risk population study.

As a part of the American-Danish prospective study of children of schizophrenic mothers, psychiatrically hospitalised and untreated cases of schizophrenia spectrum conditions, i.e. borderline schizophrenia, schizoid and paranoid personality disorders, were compared on a number of characteristics. This exploratory analysis revealed that the groups were similar to each other on childhood conditions, sociodemographic variables, premorbid IQ and levels of schizophrenia-related psychopathology. The hospitalised group, however, exhibited higher levels of concomitant psychopathology, such as substance abuse, affective symptoms and psychopathic tendencies. It is suggested that the clinical population may not be representative of the diagnostic category in question owing to co-existence of confounding symptomatology (Berkson's fallacy).