2.1. Participants

The study had got the approval of the ethics committee of the Third People's Hospital of Huzhou, Zhejiang Province, China. Patients were enrolled in the study consecutively. All participants were recruited through the third People's Hospital of Huzhou, Zhejiang Province of China. The study roadmap is shown in Fig. ​Fig.1.1. All participants were diagnosed according to the Unified Kingdom PD Society Brain Bank Clinical Diagnostic Criteria for PD^[12] and they had never taken anti-Parkinson drugs. Patients with atypical and secondary Parkinsonism were excluded from the study. All patients were in the early-stages of PD and never had FOG. They were regularly treated according to Chinese guidelines for the treatment of PD after receiving their diagnosis.^[13] Patients with anxiety or depression were diagnosed by at least one of trained psychiatrists, in addition to completing the Hamilton Anxiety Rating Scale (HAMA) and Hamilton Depression Rating Scale (HAMD). Patients with depression were treated regularly with antidepressants.

Study Roadmap. HAMA = Hamilton Anxiety Rating Scale, HAMD = Hamilton Depression Rating Scale, PD = Parkinson disease, UPDRS-III = Part III of Unified Parkinson Disease Rating Scale.

Table ​Table11 shows the demographic characteristics and clinical details of the participants at baseline. All clinical items were assessed by an experienced neurologist. The clinical data included disease duration, type of motor symptoms, site of initial motor symptoms, H&Y stage, and scores on Part III of Unified Parkinson Disease Rating Scale (UPDRS-III), the HAMD, and the HAMA. Early-onset PD (EOPD) was defined as onset at an age younger than 50 years old, whereas late-onset PD (LOPD) was defined as onset at 50 years of age or older. Patients were grouped into 3 subtypes, including tremor-dominant, akinetic-rigid, and mixed, according to the criteria described in a previous study.^[14] The UPDRS-III and H&Y stage were used to evaluate the severity of the motor symptoms. The degree of depression, anxiety, and nonmotor symptoms were assessed using the HAMA, the HAMD, and the Non-Motor Symptoms Scale (NMSS), respectively.

The demographic characteristics and clinical details of 248 participants at baseline.