Biochemical findings of negative symptoms in schizophrenia and their putative relevance to pharmacologic treatment. A review.

The most prominent biochemical finding in schizophrenic patients with negative symptoms appears to be the reduction in central dopaminergic, serotonergic and noradrenergic activity. This decrease in amine activity tends to be associated with structural brain abnormalities, i.e., cortical atrophy or enlarged ventricles. There are indications that typical neuroleptics reduce those negative symptoms of schizophrenia that are secondary to positive symptoms when these are effectively treated. However, negative symptoms of schizophrenia that occur independently of positive symptoms may also be reduced with monoamine oxidase inhibitors and atypical antipsychotic drugs, such as clozapine. The latter's efficacy seems to be related to their pharmacological profile, i.e., their interference with dopaminergic, noradrenergic and serotonergic receptor systems and metabolism.