Assessment of enduring deficit and negative symptom subtypes in schizophrenia.

The clinical importance of subtypes based on enduring deficit or negative symptoms was examined in a group of schizophrenic patients who were assessed twice over a 1-year period. Subgroups of patients with high levels of enduring negative or deficit symptoms, based on the Scale for the Assessment of Negative Symptoms and the Quality of Life Scale, had a poorer prognosis and were consistently worse in social adjustment, quality of life, and thought disorder over the year than were patients with less severe negative symptoms. Subtypes based on Andreasen's negative schizophrenia classification and on enduring thought disorder were only weakly related to other symptoms and social adjustment. Social-skill deficits were weakly related to the enduring negative symptom subtype and Andreasen's negative schizophrenia. The results suggest that enduring negative and deficit symptoms may be associated with a poor outcome in schizophrenia, including more severe positive symptoms, lower levels of social adjustment, and a poorer quality of life.