Network analysis of anxiety and depression in college students with different levels of physical activity

Anxiety and depression are the most common mental health issues among college students and often co-occur. Physical activity is an effective non-pharmacological intervention, whose beneficial effects are modulated by activity levels; however, the impact of different physical activity levels on the network structure of anxiety and depressive symptoms remains unclear. In a cross-sectional study, 2,626 college students from three universities in Guangdong Province, China, were surveyed in September 2025. The Physical Activity Rating Scale (PARS-3), the PHQ-9, and the GAD-7 were used to assess physical activity, depressive symptoms, and anxiety symptoms, respectively. A Gaussian graphical model (GGM) network was constructed using the qgraph package in R, and the network structure was estimated using the EBICglasso algorithm. Network comparison tests (NCT) were employed to analyze differences between the groups. The low physical activity group (n = 2022) had a network density of 0.688, with "uncontrollable worry" and "restlessness" as the core nodes; the strongest connections within the depression community were between psychomotor retardation and inattention. The moderate-to-high physical activity group (n = 604) had a network density of 0.562, with "difficulty relaxing" and "attention difficulties" as the core nodes. Suicidal ideation was the symptom with the highest expected bridging influence in both groups; the secondary bridging symptom was "tension" in the low-activity group and "irritability" in the moderate-to-high-activity group. Physical activity levels are significantly associated with the network structure of anxiety and depressive symptoms, with low-activity individuals exhibiting a "cognitive worry-dominated" pattern and moderate-to-high-activity individuals exhibiting a "physiological arousal-dominated" pattern. Targeted interventions may consider stratification: for low-activity individuals, cognitive worry could be a potential focus; for moderate-to-high-activity individuals, relaxation training and attention regulation may be more relevant; simultaneously, managing the risk of suicidal ideation across both groups should be prioritized.