MAOB and Parkinson disease: PD drugs, including levodopa (a dopamine [DA] precursor drug), DA receptor excitation agents, and monoamine oxidase B inhibitors, mainly target DA.[5] Nevertheless, during the late treatment stages, the above drugs elicit dyskinesia and psychiatric symptoms because of the loss of dopaminergic neurons.[6, 7] Therefore, limited drug dosage forms and single treatment strategies are major obstacles limiting the treatment of PD.