Pimavanserin, a selective serotonin receptor-modulating agent with inverse agonist/antagonist activity at 5-HT2A and, to a lesser extent, 5-HT2C receptors [1], is the first US Food and Drug Administration (FDA)-approved treatment for hallucinations and delusions associated with Parkinson’s disease (PD) psychosis [2]. Here, HTR2A is linked to Parkinson disease.