Schirmbeck and co-workers reported a reduction in OCS occurrence in schizophrenia patients treated with amisulpride, which mainly interacts with dopamine receptors, and the partial agonist of 5-HT1A aripiprazole with neutral or anti-obsessive effects compared to clozapine and olanzapine, suggesting a serotonin imbalance in schizophrenia patients with OCS [95] (Table 3). The gene discussed is HTR1A; the disease is schizophrenia.