The improvement of MDS-UPDRS III for the entire cohort (PD and APS) after PD-MCT correlated positively with MDS-UPDRS III at admission (r = 0.34; p < 0.001) and negatively with depression (rs = −0.19; p = 0.022) but not with age (p = 0.281), sex (p = 0.089), LEDD (p = 0.173), Hoehn & Yahr stage (p = 0.192), disease duration (p = 0.222), NMSQ (p = 0.724), or MoCA (p = 0.113). This evidence concerns the gene DOCK3 and major depressive disorder.