The Role of Serotonin and Dopamine in Schizophrenia

Abstract

For many years schizophrenia was attributed to an overabundance of dopamine in the brain, and until recently conventional neuroleptics (dopamine-D₂ receptor antagonists) have been the mainstay of pharmacologic treatment for patients with this illness. The dopaminergic mechanism of action makes conventional neuroleptics effective for the positive symptoms of schizophrenia but not for the negative symptoms. It is now recog nized that serotonin also plays an important role in the pathogenesis of schizophrenia. By blocking both dopamine and serotonin receptors, the newer antipsychotic agents such as clozapine, risperidone, and olanzapine are effective for both the positive and negative symptoms of schizophrenia and are less likely than conventional neuroleptics to cause extrapyramidal symptoms at prescribed doses. Although the newer antipsy chotics are tolerated better than conventional neuroleptics, each of these newer drugs is associated with some adverse effects, such as hypotension and sedation. Further research into the neurobiology of schizophrenia may lead to the development of even more effective and safe antipsychotic medications for schizophrenia. (J Am Psychiatr Nurses Assoc [1998]. 4, S30-S34.)