Differentiating primary from secondary negative symptoms in schizophrenia: a study of neuroleptic-naive patients before and after treatment.

OBJECTIVE: The study examined the primary versus secondary character of negative symptoms in a group of first-episode, neuroleptic-naive psychotic patients before and after they started neuroleptic treatment.
METHOD: Forty-seven inpatients with a first episode of schizophrenia or related psychotic disorders were examined for the presence of negative symptoms, psychosis, depression, and parkinsonism at admission to an inpatient psychiatric unit, before receiving neuroleptics, and at discharge an average 3.3 weeks later, after starting neuroleptic treatment.
RESULTS: Although patients' mean scores on measures of positive, negative, and depressive symptoms decreased significantly over the treatment period, the mean rating of nonakinetic parkinsonism worsened. The mean rating of akinetic parkinsonism did not change significantly over the treatment period. Negative symptoms at admission were not predicted by positive or depressive symptoms at admission. Residual negative symptoms at discharge were mainly predicted by negative symptoms at admission (i.e., primary symptoms) and to a negligible degree by residual positive and depressive symptoms. Change in negative symptoms over the observation period was predicted to a marginal degree by change in depressive symptoms.
CONCLUSIONS: Negative symptoms rated during a first psychotic episode before and after starting antipsychotic treatment are mainly primary in character and should be considered as a direct manifestation of the basic dysfunctions of schizophrenia.