Metabolic dysfunction-associated fatty liver disease （MAFLD） is the chronic liver disease with the highest prevalence rate globally， and its disease spectrum encompasses a progressive continuum from hepatic steatosis to metabolic dysfunction-associated steatohepatitis， liver fibrosis， liver cirrhosis， and eventually hepatocellular carcinoma. In recent years， the research paradigm of MAFLD has shifted from “lipid accumulation” to “lipid metabolic reprogramming”， which， as a critical link in disease development and progression， is regulated by multidimensional molecular networks. This article systematically reviews the molecular mechanisms of lipid metabolic reprogramming in MAFLD from the following aspects： it analyzes the core role of lipid metabolism disorders， with a focus on how dysregulation of membranous organelle interactions， such as endoplasmic reticulum-mitochondria contacts， mediates metabolic imbalance； it concentrates on novel programmed cell death pathways induced by lipotoxicity， especially ferroptosis， and reveals the pathways through which they exacerbate liver injury； furthermore， it comprehensively analyzes the multi-layered regulatory network of the key signaling pathways such as adenosine monophosphate-activated protein kinase and nuclear factor-erythroid 2-related factor 2 and explores the emerging mechanisms such as liquid-liquid phase separation and microprotein regulation； finally， it provides an outlook on the potential therapeutic strategies targeting critical nodes of lipid metabolic reprogramming， so as to provide a theoretical basis for investigating the pathological mechanisms of MAFLD and developing precise interventions.

ObjectiveTo systematically review the association between non-alcoholic fatty liver disease （NAFLD） and depression， and to provide a basis for synergistic management in clinical practice. MethodsThis study was conducted according to the PRISMA guidelines， with the PROSPERO registration number of CRD42023482013. PubMed， Embase， the Cochrane Library， Web of Science， CNKI， Wanfang Data， VIP， and CBM were searched for articles on the association between NAFLD and depression published up to November 1， 2024. The articles were screened according to the inclusion and exclusion criteria， and related data were extracted. RevMan 5.3 was used to perform the Meta-analysis. ResultsA total of 18 studies were included， involving 396 793 participants. Among these studies， 12 discussed the influence of NAFLD on depression， involving 224 269 participants， among whom there were 75 574 patients with NAFLD. The Meta-analysis showed that NAFLD was significantly associated with the risk of depression （odds ratio ［OR］=1.21， 95% confidence interval ［CI］： 1.12 — 1.30， P0.001）. Six studies examined the influence of depression on NAFLD， involving 172 524 participants， among whom there were 29 368 patients with depression. The meta-analysis showed that depression caused a significant increase in the risk of NAFLD （OR=1.13， 95%CI： 1.05 — 1.22， P=0.001）. ConclusionThere is a significant bidirectional association between NAFLD and depression. It is recommended to perform the screening for depression and enhance mental health monitoring in patients with NAFLD， and metabolic function assessment and exercise intervention should be performed for patients with depression.