Validity of the depressive dimension extracted from principal component analysis of the PANSS in drug-free patients with schizophrenia.

Depressive symptoms frequently occur during the course of schizophrenia. This study explored the relationships between the schizophrenia symptomatology and three measures of depression. Eighty-one drug-free inpatients with acute schizophrenia were assessed with the positive and negative syndrome scale (PANSS), the Calgary depression scale for schizophrenia (CDSS), and the Hamilton rating scale for depression (HAM-D).