DRD2 and major depressive disorder: Our results on the effects of PPHT may have implications in the understanding of the molecular bases of schizophrenia and major depression, since decreased levels of dopamine [24], [25] and D2R [26], [27], as well as deficits in GABAergic neurotransmission and PV expressing interneurons have been found in the PFC of patients and animal models of these disorders [28], [29].