Objectives Some heavy metals are suspected to be pathogenic to both Parkinson's disease (PD) and depression. Common background may exist in them. Methods Subjects comprised PD patients with depression, PD patients without depression and controls recruited from the outpatient clinic in China. Morning blood and urine samples were used to measure concentrations of metals and vitamins. Results Whole-blood manganese was significantly higher in the PD patients without depression than in both the PD patients with depression and the controls. Serum iron was significantly higher in the PD patients without depression than in the controls. Urine iron was also significantly higher in the PD patients without depression than in the controls. Serum copper was significantly lower in the PD patients with depression than in both the PD patients without depression and the controls. Conclusions Excessive intake of iron and accumulation of manganese seemed to be involved in the etiology of non-depressive PD
