Recently, a study of PD patients from China and the Parkinson’s Progression Markers Initiative (PPMI) cohort has indicated that although the MAOB rs1799836 polymorphism was linked to the progression of non-motor symptoms of the patients in general in the Chinese cohort, there was no specific association with the progression of depression or anxiety in both cohorts [8]. This evidence concerns the gene MAOB and depressive symptom measurement.