Negative Symptoms of Schizophrenia: Methodological Issues, Biochemical Findings and Efficacy of Neuroleptic Treatment

Negative symptoms (minus symptoms) are defined increasingly as a focus of interest both for etiopathogenetic research and psychopharmacological research. However, the findings in both areas are often contradictory, which might be explained by basic methodological problems in the clinical definition and description of the syndrome. Therefore in the first part of this article some of these methodological issues will be shortly reviewed. In the second part a review of biochemical findings will be given. The last part is devoted to the evaluation of the neuroleptic treatment.