The positive:negative dichotomy in schizophrenia.

Two studies are reported. In the first, of 62 schizophrenic patients, no correlation between negative symptom scores (rated blindly) and any measure of positive symptoms was found. This independence was confirmed by factor and cluster analyses, which left the question of a third 'disorganisation' class of schizophrenic symptoms open. In the second study, of 80 patients, formal thought disorder separated unequivocally into 'positive formal thought disorder' and 'alogia' syndromes on the basis of correlations with positive and negative symptoms. Catatonic motor disorder also showed evidence of a corresponding positive: negative division, although this only emerged when severity or chronicity of illness was controlled for. Cognitive impairment showed a broad range of affiliations and its particular correlation with negative symptoms was perhaps artefactual.