AUTHOR=Shi Mingqin , Li Xinyao , Zhou Haimei , Li Zhenmin , Wei Yuanyuan , Wang Zihui , She Yuqing , Zou Xuelian , Xiao Xiangdian , Zeng Jiashun , Qin Dongdong TITLE=Rheumatoid arthritis-associated depression: focusing on the interactions between mitochondria and endoplasmic reticulum JOURNAL=Frontiers in Pharmacology VOLUME=Volume 16 - 2025 YEAR=2025 URL=https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2025.1549060 DOI=10.3389/fphar.2025.1549060 ISSN=1663-9812 ABSTRACT=The interplay between mitochondria and endoplasmic reticulum (ER) is essential for cellular viability. The structures known as mitochondria-associated endoplasmic reticulum membranes (MAM) provide complicated connections between these organelles, which house a variety of proteins, each serving distinct roles across different cellular environments. Growing evidence indicates that disruptions in mitochondrial-ER interactions are linked to immune and inflammatory responses. The concurrent presence of rheumatoid arthritis (RA), an immune-mediated inflammatory condition, and depression has been well-documented. Alterations in proteins that mediate mitochondrial-ER interactions and MAM functionality are increasingly correlated with immune and inflammatory pathways. This suggests that a comprehensive understanding of disease mechanisms can be enhanced by examining the alterations in their intercommunication rather than viewing the organelles in isolation. In this review, we explore the pathophysiological mechanisms underlying RA in conjunction with depression, the relationships among mitochondria, the endoplasmic reticulum, mitochondrial-ER interactions, and their association with RA-associated depression, and propose that targeting MAM could offer a novel therapeutic approach for managing RA-associated depression.