Objective To investigate the association of serum neurofilament light chain(NFL)and glial fibrillary acidic protein(GFAP)with Parkinson disease(PD)with anxiety and depression.Methods A total of 96 PD patients and 38 healthy controls were enrolled in this study.Hamilton Anxiety Scale(HAMA)and Hamilton Depression Scale(HAMD)were used to evaluate anxiety and depression in the PD patients,and the patients were divided into groups based on their diseases.Ultrasensitive single molecule array(Simoa)was used to quantitatively measure the serum levels of NFL and GFAP.The levels of NFL and GFAP were compared between groups;Spearman correlation analysis and logistic re-gression analysis were used to investigate the association of NFL and GFAP with anxiety and depression in PD patients;the receiver operating characteristic(ROC)curve was used to access the value of GFAP level in the diagnosis of PD with de-pression.Results Compared with the healthy control group,the PD patients with or without anxiety and depression had a significant increase in the level of NFL(P＜0.001),and compared with the PD patients without depression or anxiety,the PD patients with depression or anxiety had a significant increase in the level of GFAP(P＜0.05).In the PD patients,the serum level of GFAP was positively correlated with the degree of anxiety(r=0.271,P=0.008)and depression(r=0.302,P=0.003).After adjustment for confounding factors,the logistic regression analysis showed that GFAP remained an inde-pendent risk factor for depression in PD patients(P=0.028).The ROC curve analysis showed that GFAP had an area un-der the ROC curve of 0.660 in the diagnosis of PD with depression.Conclusion Serum GFAP level is associated with anxiety and depression in PD and is an independent risk factor for PD with depression.