IntroductionPrevious studies have shown disrupted effective connectivity in the large-scale brain networks of individuals with major depressive disorder (MDD). However. it is unclear whether these changes differ between first-episode drug-naive MDD (FEDN-MDD) and recurrent MDD (R-MDD). MethodsThis study utilized resting-state fMRI data from 17 sites in the Chinese REST-meta-MDD project. https://www.foldlyers.shop/product-category/preamplifiers/