Analysis of positive and negative symptoms in schizophrenia. A study from a population of long-term outpatients.

Sixty-seven schizophrenic chronic outpatients (DSM-III-R criteria) were examined to study the relationship between symptoms through intercorrelational and factor analysis. Three factors were identified and associated with clusters of symptoms: factor 1 (affective flattening, alogia, avolition-apathy and anhedonia-asociality), factor 2 (formal thought disorder and bizarre behaviour) and factor 3 (hallucinations and delusions). Strong associations between factor 1 and high functional impairment were found. In this population, the segregation of the symptoms could fit into a three-syndrome model, these results agree with findings obtained from samples in which acute symptoms predominated.