Depression diagnosis through emotional induction and physiological signals: A systematic review

Depression is a severe mental disorder that significantly disrupts an individual's emotional stability and, consequently, their overall quality of life. Traditional diagnostic approaches face limitations, particularly due to subjective biases and resource constraints, prompting increased interest in objective, physiologically-based diagnostic methods. While it is well-established that individuals with depression exhibit marked emotional differences from healthy controls, the specific patterns of emotional responses and physiological signals in response to emotional induction remain insufficiently explored. This review aims to investigate how depressive individuals respond to emotional stimuli, with a particular focus on how these emotional responses can be objectively assessed through physiological signals. A systematic review is conducted by searching PubMed, Web of Science, and Scopus, yielding 1346 results. After applying predefined inclusion criteria, 51 studies are selected for narrative synthesis. The review provides a comprehensive overview of (a) emotion models, (b) emotional stimuli materials and tasks, (c) physiological signals associated with emotional responses, (d) methodologies and devices for measuring these signals, and (e) differences in physiological responses between depressive patients and healthy controls under specific emotional inductions. Furthermore, the review discusses the influence of experimental settings and participant differences on results, as well as considerations regarding the selection, combination, and acquisition of physiological signals. These insights have important implications for advancing both research and clinical auxiliary diagnostic practices for individuals with depression.