What did the dopamine hypothesis of schizophrenia originally propose?

1. Interest in dopamine grew from two findings: drugs raising dopamine can produce schizophrenia-like symptoms, and drugs blocking it reduce symptoms. 2. The hypothesis proposed that an overabundance of dopamine, or too many dopamine receptors, drives the onset and maintenance of schizophrenia. 3. Blockade by medication is the evidence for the hypothesis rather than the hypothesis itself, which is the trap in this item. 4. A brain-wide shortage runs opposite to the original proposal, though later work found low prefrontal dopamine alongside limbic excess. 5. Newer antipsychotic medications work by blocking serotonin receptors, which is why serotonin has drawn attention more recently. _Source: OpenStax Psychology (1st ed., CC BY 4.0), Ch 15 "Psychological Disorders", section 15.8 Schizophrenia_