The role of the amygdala in depression: a bibliometric analysis (2015-2024).

Background: Depression is a highly heterogeneous disorder with complex mechanisms. Given converging evidence implicating the amygdala in its pathophysiology, a systematic and quantitative synthesis is warranted to map the research landscape, hotspots, and emerging trends. Objective: To systematically characterize the research landscape of depression-amygdala studies from 2015 to 2024 using bibliometric and visualization analyses, identify core hotspots and emerging themes, and track their evolution to inform subsequent mechanistic research and precision interventions. Methods: Using data from the Web of Science Core Collection and Scopus (2015-2024), we conducted a bibliometric analysis of English-language publications on depression and the amygdala with Bibliometrix and VOSviewer. Publication trends, country and institutional contributions, highly cited papers, and keyword co-occurrence/clustering were analyzed to delineate the field's structure and evolution. Results: A total of 5,999 publications were included. Annual output increased steadily from 399 in 2015 to a peak of 831 in 2024. The United States (1,813, 30.2%), China (1,122, 18.7%), and Germany (357, 6.0%) were the top contributors. The ratio of multi-country publications (MCP) was highest for Germany (28.3%), followed by the United Kingdom (28.1%) and Canada (24.6%). At the institutional and journal levels, the University of California system, Harvard University, and Harvard Medical School ranked among the leading contributors. The international collaboration network exhibited a U.S.-centered structure, with frequent partnerships between the United States and China (n = 113), the United States and the United Kingdom (n = 86), and the United States and Germany (n = 81). Keyword co-occurrence and clustering analyses revealed four major thematic clusters: emotion regulation networks, biological signaling and regulation, developmental risk factors, and animal models. Overall, the field has evolved from region-specific studies toward network- and system-level integration, highlighting the amygdala's pivotal role in the neurobiological mechanisms of depression and its potential as a candidate neuromarker. Conclusion: Bibliometric evidence indicates that research on depression-amygdala relationships is moving toward multi-dimensional and cross-disciplinary integration. The amygdala's involvement in emotion regulation and early-life stress is increasingly recognized; alterations in its functional connectivity show promise as a neuromarker of depression, though clinical translation requires multi-center validation and standardized analytic workflows.