Is lifestyle a bridge between perceived social support and depression in Chinese university students?

University students are at a high-risk group for depression, with increasing numbers of students experiencing this mental health condition. Previous research has shown a negative relationship between perceived social support and depression among university students. However, few studies have used lifestyle as a mediating variable when exploring the mediating mechanisms underlying this relationship. Based on the main-effect model of social support, this study examined the potential efficacy of perceived social support in alleviating depressive symptoms among Chinese university students, taking into account the mediating influence of lifestyle. To test these hypotheses, 1043 university students (n = 1006 after data processing) from 6 universities in Northwest China were selected through a combination of convenience sampling and cluster sampling methods. The collected survey data were analyzed using structural equation model (SEM). The results revealed a significant negative association between perceived social support and depression among Chinese university students. Moreover, lifestyle was found to partially mediate the relationship between perceived social support and depression. Notably, only one specific lifestyle behavior, namely sleep quality, passed the mediation test, suggesting that sleep quality serves as the actual mediating variable rather than the broader construct of lifestyle itself. These findings underscore the importance of establishing a robust social support network and healthy lifestyle, with particular emphasis on cultivating healthy sleep habits. Such interventions hold promise for alleviating depressive symptoms, reducing the risk of depression, and maintaining the mental well-being of university students.