To explore the relative contribution of multidimensional influential factors on depressive symptoms among college students and to compare the differences in key influencing factors between different years, to provide evidence for the preventive intervention of depression among current college students.

Clinical medicine students from a medical university were selected as research subjects in 2011 and 2024, respectively. The center for epidemiological studies depression scale (CES-D), life events scale, and social support rating scale were used to assess depressive symptoms, recent negative life events, and social support levels. Network analysis was employed to construct networks of life events, social support, and depressive symptoms among university students. The association strengths between different dimensions of life events, social support, and depressive symptoms were analyzed to identify the most central "symptoms" and activating factors within the networks. Network comparison tests (NCT) were used to explore differences between the networks of the two years.

The detection rates of depressive symptoms among college students in the two survey years were 28.3% and 37.1%, respectively. Statistically significant differences (P < 0.05) were observed in scores for objective support (t=101.68), subjective support (t=7.31), total social support (t=50.93), loss factor (t=2.54), punishment factor (t=-3.62), academic factor (t=5.19), and other factors (t=-8.57). Were statistically significant. Varying strengths of association were found between different dimensions of depressive symptoms and recent negative life events and social support among college students. The node with the highest expected influence (EI) in both years was D1 (depressive mood). The node with the highest bridge expected influence (BEI) was D3 (somatic symptoms) and D1 (depressive mood) in the respective years. Network comparison test results showed a statistically significant difference in the overall network strength between the two years (Global Strength₂₀₁₁=3.83, Global Strength₂₀₂₄=4.40, P < 0.001). The EI values of E2 (punishment factor), E5 (health adaptation factor), SS1 (objective support), and SS2 (subjective support) differed significantly between the year groups (P < 0.001). The BEI values of SS2 (subjective support) and D3 (somatic symptoms) also differed between the year groups (P=0.01).

The detection rate of depressive symptoms among college students in 2024 was higher than that in 2011, and the pattern of associations between social support, recent negative life events, and depressive symptoms has changed. The findings highlight the important roles of academic pressure, peer relationships, and social support for contemporary college students.