Association between multiple health behaviors and mental health in Chinese college students: a cross-sectional study

Background College students face significant psychological pressures, yet the cumulative effects of multiple concurrent health behaviors on their mental health remain underexplored, particularly in the Chinese context. Methods A cross-sectional survey was conducted among 521 college students from Shandong and Guangdong provinces, China. Health behaviors, including physical activity (IPAQ-C), sedentary behavior (SBQ), sleep quality (PSQI), smoking, and alcohol use, were assessed via validated self-report questionnaires. Mental health outcomes were measured using the Personal Wellbeing Index (PWI) and the Depression, Anxiety, and Stress Scales-21 (DASS-21). Multiple linear regression analyses, adjusting for key demographic covariates, were employed to examine associations. Results Prolonged screen time was consistently associated with poorer mental health, showing negative correlations with personal wellbeing (β = −0.03, P = 0.036) and positive correlations with stress (β = 0.24, P = 0.030), depression (β = 0.32, P = 0.005), and anxiety (β = 0.25, P = 0.020). Alcohol consumption was negatively associated with personal wellbeing (β = −0.16, P = 0.040). Interestingly, smoking was negatively associated with stress (β = −1.37, P = 0.020) and depression (β = −1.44, P = 0.016). Physical activity (MVPA) showed no statistically significant associations with stress (β = 0.01, P = 0.750), depression (β = 0.01, P = 0.630), or anxiety (β = −0.001, P = 0.490) in the regression models. Furthermore, no significant gender differences were observed in the key health behaviors or mental health scores. Conclusion Unhealthy behaviors, particularly high screen time and alcohol use, are significantly associated with adverse mental health outcomes among Chinese college students. The findings suggest that smoking might be used as a maladaptive coping mechanism. Public health interventions should adopt an integrated approach, simultaneously targeting these co-occurring behavioral risk factors to promote student wellbeing.