We also found that the APOE ε4 allele was significantly associated with hyperhidrosis (OR = 3.472, 95%CI: 1.082–11.144, p = 0.036) and depression (OR = 3.002, 95%CI: 1.079–8.353, p = 0.035) in DLB patients, while there were no significant associations between APOE ε4 allele and the age at visit, the age at onset, scores of MDS-UPDRS III, H&Y stage, ADL, MMSE, MOCA and NPI, as well as the presences of fluctuating cognition, VH, parkinsonism and RBD in both groups. This evidence concerns the gene APOE and major depressive disorder.