[Psychological and social anhedonia. Evaluation of a research instrument for measuring a basic psychopathologic disorder].

Scales for the measurement of social and physical anhedonia, the lowered ability to experience pleasure, were investigated. Both scales were devised by Chapman et al. German versions of these two patient populations and two groups of normal subjects. The reliability and scale intercorrelation coefficients were acceptable for the scales overall, but not for the separate subscales. Patients scored higher on both scales than normal subjects, and patients with neurotic depression had higher scores than those with a diagnosis of schizophrenia. A significant correlation with a chronic course was identified in the schizophrenic patients. Item analysis and factor analysis did not reveal any significant common dimensions in the 87 items in the original scales. Only 17 items in the physical anhedonia scale and 26 items in the social anhedonia scale met test-theoretical criteria of acceptability for inclusion in a German version of these scales. Discrepancies and congruencies between American and German studies were discussed, as were further criteria that might make it possible to improve research instruments of this kind.