Magnetic resonance imaging study of major depressive disorder: a 28-year scientometric and visual analysis

Neuroimaging, particularly magnetic resonance imaging (MRI), has become a cornerstone in elucidating the neural underpinnings of Major Depressive Disorder (MDD). As the volume of related literature grows rapidly, a systematic, quantitative overview of the field's development, intellectual structure, and emerging trends is essential. This study conducted a scientometric and visual analysis of MRI research on MDD over the past 28 years (1997-2025) using data extracted from the Web of Science Core Collection. A total of 3269 publications were analyzed with CiteSpace and VOSviewer to map collaboration networks, thematic evolution, and research fronts. The results show a steady increase in annual output, particularly after 2006, driven by advances in 3T MRI and the pursuit of objective biomarkers. The United States and China are the most productive countries, while Harvard University and the University of California System lead institutional contributions. Co-citation and keyword analyses reveal a paradigm shift from localized structural/functional deficits toward network-based perspectives, alongside methodological evolution toward multimodal integration, dynamic analyses, and machine learning. Current research fronts focus on suicidal ideation, treatment prediction, and neuromodulation. This study provides a macroscopic overview of the field's trajectory, highlighting key contributors, thematic transitions, and future challenges in translating neuroimaging findings into clinical practice.