Finally, while more research is needed in this direction, mirtazapine and olanzapine could play a major role in PI-OCD augmentation strategies for patients taking high (sometimes off-label) doses of SSRIs, and their 5-HT3 blockade may substantially contribute to the management of drug-induced nausea, even if as in this case it remains unclear which one of the two medications might have had most contribution to cessation of nausea or contribution to compliance lasting for at least 1 year. The gene discussed is HTR3A; the disease is Nausea.