## 5 Discussion  
The network analysis of the professional title dimension reveals the hierarchical characteristics of the medical system. The chief physician network shows a high degree of internal connectivity, reflecting the core position of senior physicians in the dissemination of professional knowledge and the integration of resources. In contrast, the residency network appears relatively closed and fragmented, highlighting the gradient character of medical professional development. The conclusion of this study reveals the heterogeneity of physician groups with different professional titles in the medical collaboration network. From the perspective of network topological structure attributes, chief physicians, with their ability to integrate information resources and advantages in structural holes endowed by their senior titles, have significant advantages in core indicators such as Degree Centrality and Betweenness Centrality. The formation mechanism of this difference can be attributed to three dimensions: First, the occupational role division dimension, senior physicians through leading multidisciplinary diagnosis and treatment, difficult case consultation and other collaborative scenarios, to build a cross-department strong connection network, the subgroup of which shows a higher density and clustering coefficient; second, the dimension of knowledge dissemination. As the pivotal node of clinical experience and scientific research information, chief physicians effectively promote the transfer and diffusion of tacit knowledge through vertical guidance and horizontal coordination, thus strengthening the cohesion of the network. [PERSON] and [PERSON] (2020) pointed out in their study that key opinion leaders (Kols) play a core role in the knowledge diffusion process in the medical network, and high school psychological physicians significantly improve the overall knowledge level and innovation ability of the network through frequent interaction and information sharing [37], which is consistent with the conclusion of this study. Third, in the dimension of career development trajectory, residents are limited by the hierarchical characteristics of the training system and the rules of the career life cycle, and their social networks show significant local aggregation, which is significantly correlated with the growth path and resource acquisition mechanism of junior physicians. [PERSON] and [PERSON] (2020) found through the analysis of social networks that, Junior physicians rely on tight local networks in the process of resource acquisition, which not only limits the breadth of their networks, but also affects the diversity and flexibility of their professional development [38], which is also confirmed by the conclusion of this study. Figure 5: Box plot of Regression Relationship Between Doctor Recommendation Rate and Post-Consultation Evaluation. The analysis of the disease-type network deeply reveals the functional differences and internal organizational logic of the medical profession and presents the uniqueness and complexity of the disease field in the construction of a professional network. The depression network exhibits significantly different network characteristics from other disease types, and its unusually dense internal connections reflect multi-level professional collaboration mechanisms. From the point of view of the complexity of diagnosis and treatment, depression is a disease involving physiological, psychological, and social dimensions, and its medical network shows a high degree of interdisciplinary integration. This network structure may stem from several deep-seated reasons: First, the highly professional nature of depression diagnosis and treatment requires the medical team to have the comprehensive ability to cross fields. Unlike diabetes, which is a relatively single physical disease, depression requires the coordinated treatment of psychiatry, psychology, neurology, endocrinology, and other disciplines.