Negative symptoms: a path analytic approach to a double-blind, placebo- and haloperidol-controlled clinical trial with olanzapine

Abstract

These results suggest that the negative symptoms of schizophrenia are directly responsive to treatment. The significantly greater direct and indirect effects of olanzapine than of haloperidol on negative symptoms are likely related to olanzapine's pleotrophic pharmacology, which includes dopaminergic, serotonergic, muscarinic, and adrenergic activities. The results contribute to the hypothesis that negative symptoms may be under the influence of several neurotransmitters within one or more neuroanatomic circuits.