[Validation of positive and negative symptom scale (PANSS) in a sample of Spanish schizophrenic patients]

We analyzed the reliability and validity issues of the Positive and Negative Syndrome Scale (PANSS) in a sample of 100 DSM-III-R schizophrenic patients. Our findings coincided with the results of the scale authors in the following points: 1) the PANSS scores were normally distributed, 2) the positive and negative scales showed a good interrater reliability, 3) the construct validity was appropriate, 4) the positive and negative scales held a high criterion-related validity in relation to SAPS and SANS. Unlike to the authors of the PANSS, we found a modest internal consistency and an insufficient factorial validity of the positive scale, indicating that it is composed by several independent components. The data suggest that the distinction between positive and negative symptoms is an oversimplification, and that schizophrenic symptoms can be better conceptualized as being composed by, at least, three dimensional syndromes: positive, disorganization and negative.