Psychometrically Assessed Thought Disorder in Schizophrenic and Control Patients and in their Parents and Siblings

Thought disorder has always been regarded as an important symptom of schizophrenia. Attempts have been made to measure it by means of psychological tests: patients who manifest thought disorder clinically have been found to perform idiosyncratically on tests of concept-formation (1). The purpose of the first part of this investigation was to confirm the already established finding that schizophrenics, as a whole, are more thought disordered than controls. Not only were patients tested, but also their first-degree relatives; this aspect of the investigation, however, will be dealt with in the second part of the paper.