AMP (PAS) and BPRS: a comparison of two assessment methods.

The aim of this investigation was to contribute to the validation of the AMP(PAS) system. As a criterion we used the BPRS because it has been accepted as one of the most widely used scales in the English-speaking countries. Our study includes the following steps: a) comparison of AMP syndromes and BPRS dimensions by computation of a factor analysis of both scales; b) comparison of each homogeneous group found by cluster analysis techniques of the AMP with its values on the BPRS: c) comparison of discriminative power of both scales concerning different groups (nosological or found by cluster analysis) by discriminant analysis. In a sample of 70 female patients with acute psychiatric symptoms we found that both scales describe psychopathological phenomena and classify patients in a very similar way. However, we were able to classify patients into homogenous groups by cluster-analysis techniques in a more consistent manner with AMP than with BPRS. Both scales gave better results in description and classification of psychoses than of neuroses, although the AMP system separates psychotic patients from neurotic patients more accurately than the BPRS. Our results suggest that the AMP system permits a more differentiated psychopathological description and a more accurate and consistent classification of psychiatric patients than the BPRS, at least in the special patient sample used for this investigation.