DRD2 and schizophrenia: Cariprazine is the first available antipsychotic that preferentially acts as a partial agonist at D3R, with Ki = 0.085 nM, higher than the one for the D2R (Ki = 0.49 nM) [48], demonstrating significantly better efficacy on prevalent negative symptoms in schizophrenia patients compared to a full D2R antagonist, such as risperidone [49,50].