Abstract:ObjectiveTo investigate the causal relationship between psychiatric and psychological disorders（depression,bipolar disorder， and schizophrenia) and non-alcoholic fatty liver disease （NAFLD). Methods The two-sample Mendelian randomization(MR)method was adopted, with depression,bipolar disorder, and schizophrenia as exposure variables and NAFLD as the outcome variable.The single nucleotide polymorphisms (SNPs) independently associated with exposure variables were obtained from the summary data of the genome-wide association study （GWAS) as instrumental variables for MR analysis. The analysis results of the inverse-variance weighted (IVW) were used as the primary outcome indicators,while those of the MR Egger regression method, weighted median, and weighted mode as supplementary results. The Cochran's Q test,MR-Egger intercept, and "leave-one-out" method were used for sensi-tivity analysis. ResultsThe results of IVW analysis showed that depression was positively correlated with the incidence risk of NAFLD (OR=1.21,95%CI;1.01-1.44,P<0.05)，while bipolar disorder was negatively correlated with the incidence risk of NAFLD(OR=0.91,95%CI;0.84-1.0O,P