HTR2A and schizophrenia: While dogma dictates that dopamine dysfunction is central to the pathogenesis of schizophrenia [4], the paradigm-breaking observation was that pure serotonin 5-HT2A antagonist, primavanserin, which does not directly modulate dopaminergic receptor activity, was proven effective in treatment of psychotic symptoms secondary to Parkinson’s disease or dementia [5], suggesting a direct implication of serotonin dysfunction in psychosis.