The stability of symptoms and syndromes in chronic schizophrenic patients.

36 chronic schizophrenic patients meeting D.S.M. III - R criteria were assessed by a single rater using the Positive and Negative Syndrome Scale (PANSS). Ratings were repeated 9 months later by the same rater. Negative symptoms and syndromes were much more stable over time than positive symptoms and syndromes. Only hallucinations had stability comparable to the negative symptoms. Positive and negative subtypes of schizophrenia based on the composite score were very stable. Relatively few symptoms from the general psychopathology subscale were stable over time. The implications of these findings are discussed.