Briefly explain the original dopamine theory of schizophrenia.Why was it considered too simplistic?

Key terms and concepts that may be included in student responses:
▪ Original dopamine theory-the symptoms of schizophrenia are caused by excess levels of dopamine in the brain, particularly in the prefrontal cortex and limbic system
▪ Supporting evidence-a group of drugs that tend to reduce the symptoms of schizophrenia the phenothiazines or neuroleptics, reduces the functional level of dopamine in the brain, drugs that increase the functional level of dopamine in the brain, tend to increase the positive symptoms of schizophrenia, neuroimaging studies suggest the presence of more receptors for dopamine and higher levels of dopamine in some areas of the brain in people with schizophrenia than in people without the disorder
▪ Simplistic nature-many people with schizophrenia do not respond to the phenothiazines; even people with schizophrenia who respond to the phenothiazines tend to experience more relief from positive symptoms than from negative symptoms; levels of dopamine change relatively soon after drug therapy begins, while changes in symptoms often take longer