Natural history of schizophrenia subtypes. II. Positive and negative symptoms and long-term course.

The natural history and long-term course of schizophrenia divided by pervasiveness of positive and negative symptoms was explored among 187 schizophrenic patients from the Chestnut Lodge follow-up study. Schizophrenia with many negative symptoms was associated with poor premorbid functioning, insidious onset, partial or no remissions during the first several years of illness, and in most cases a progressive course leading to permanent disability. Schizophrenia with few negative symptoms was associated with good premorbid functioning, acute onset, intermittent early course, and a better prognosis. Positive symptoms predicted future hospitalizations but were less powerful and specific as indicators of differential illness history, course, and long-term functional incapacity. As predictors of long-term outcome, negative symptoms were of greater value measured at index admission several years after illness onset than at first hospital admission. Multivariate analyses indicated that two negative symptoms (anhedonia and affective flattening) contribute significantly to outcome variance independent of their association with premorbid functioning or positive symptoms. Patients with the poorest long-term outcome tended to show an increase in negative symptoms during the early years of their illness. Progressive negative symptoms early in the course of schizophrenia may thus reflect or signal a process leading to long-term functional disability.