Associations of mean striatal DAT binding with clinical measures in cross‐sectional analysis. Cross‐sectional associations of mean striatal DAT binding with clinical measures were shown (a). PD individuals with higher Hoehn and Yahr scales (b), freezing of gait (c), and initial rigidity symptoms (d) contribute to lower striatal DAT binding levels. PD men who had higher Hoehn and Yahr scales (e) and freezing of gait (f) showed lower striatal DAT binding. Healthy controls who had severe olfactory dysfunction presented lower striatal DAT binding (g). *FDR‐adjusted p < 0.05; and nominal p < 0.05 whereas FDR‐adjusted p ≥ 0.05. Nominal p values were demonstrated in (b–f). DAT, dopamine transporter; ESS, Epworth Sleepiness Scale; FDR, false discovery rate; GDS, Geriatric Depression Scale; HC, healthy control; MDS‐UPDRS, Movement Disorder Society‐Sponsored Revision of the Unified Parkinson Disease Rating Scale; MoCA, Montreal Cognitive Assessment; PD, Parkinson's disease; RBD, rapid‐eye‐movement sleep behavior disorder; RBDSQ, rapid‐eye‐movement sleep behavior disorder screening questionnaire; SCOPA, Scales for Outcomes in Parkinson's disease – Autonomic.