Effect of neuroleptics on positive and negative symptoms and the deficit state.

The concept of negative symptoms tries to operationalize a deficit syndrome observed in schizophrenia, but also in other disorders. The instruments for the measurement developed so far are unclear in their dimensional structure and validity. Further methodological development is needed. A new scale for measuring negative symptoms was derived from the AMDP-system and applied to results of drug trials with clozapine, fluperlapine, and haloperidol. The three drugs were equally effective on negative symptoms of acute and chronic schizophrenics.