Ego-pathology and common symptom factors in schizophrenia.

The phenomenological construct of ego-pathology in schizophrenia has been widely referred to in psychopathological textbooks but was systematically assessed in very few empirical studies. This study investigated the association between ego-pathology (Ego-Pathology Inventory) and common symptom factors (Positive and Negative Symptom Scale) in paranoid schizophrenia patients within 3 days after admission and after 2 weeks of treatment. The predictive value of ego-pathology for short-term treatment outcome was also assessed. A factor analysis of all subscale scores revealed a four-factor solution: positive symptoms, negative symptoms, and two distinct ego-pathology factors, i.e., general and identity. Although the ego-pathology subscale "activity" loaded on the positive symptom factor, the other four subscales formed the two ego-pathology factors with no high loadings on other factors. High scores on ego-demarcation at admission predicted poor treatment outcome after 2 weeks. The findings suggest that ego-pathology might be used to capture additional and clinically meaningful symptom dimensions in schizophrenia.