HTR2A and psychotic disorder: 5-HT (serotonin) receptors are targeted by multiple antipsychotics, and the specific 5-HT2A antagonist pimavanserin has recently been approved for the treatment of psychosis in parkinsonian patients (Bozymski et al., 2017; Kianirad and Simuni, 2017; Sahli and Tarazi, 2018).