Causal relationships between neuropsychiatric disorders and nonalcoholic fatty liver disease: A bidirectional Mendelian randomization study

Abstract

Abstract Background and Aims : Increasing evidences suggest that nonalcoholic fatty liver disease is associated with neuropsychiatric disorders. Nevertheless, whether there were causal associations between them remained vague. A causal association between neuropsychiatric disorders and NAFLD was investigated in this study. Methods We assessed the published genome-wide association study summary statistics for NAFLD, seven mental disorder-related diseases and five central nervous system dysfunction-related diseases. The causal relationship was first assessed using two-sample Mendelian randomization. Then, sensitivity analyses were performed, followed by a reverse MR analysis to determine whether reverse causality is possible. Finally, we performed replication analyses and combined the findings from the above studies. Results Our results showed NAFLD significantly increased the risk of anxiety disorders (OR = 1.016, 95% CI = 1.010–1.021, P value <0.0001). In addition, Major Depressive Disorder was the potential risk factor for NAFLD (OR = 1.233, 95% CI = 1.063–1.430, P value = 0.006). Furthermore, other neuropsychiatric disorders and NAFLD were not found to be causally related. Conclusion These results implied causal relationships of NAFLD with anxiety disorders and Major Depressive Disorder. This study highlighted the need to recognize and understand the connection between neuropsychiatric disorders and NAFLD to prevent the development of related diseases.