Physical exercise moderates the mediating effect of depressive symptoms between sleep quality and suicidal ideation among college students.

Sleep quality is critical for suicidality or psychological well-being in any cohort. However, the underlying psychological and behavioral mechanisms linking these factors remain insufficiently understood. In this study, we investigated the association between sleep quality and suicidal ideation, exploring the mediating role of depressive symptoms and the moderating effect of physical exercise in this relationship. A cross-sectional survey was conducted across six universities in Guangdong Province using the stratified sampling method. Variables were assessed using the Pittsburgh Sleep Quality Index (PSQI), the subscale of the Beck Scale for Suicide Ideation-Chinese Version (BSS-C), the Short-form Depression Scale, and Physical Activity Rating Scale (PARS-3). The interrelationships between sleep quality, suicidal ideation, depressive symptoms, and physical exercise among college students were examined using a moderated mediation model to elucidate their complex interactions. Poor sleep quality had a positive effect on college students' suicidal ideation, and depressive symptoms played an intermediary role in this relationship. Furthermore, physical exercise moderated the relationship between sleep quality and depressive symptoms, highlighting its potential protective role. These findings underscore the importance of enhancing sleep quality among college students as a preventive measure against suicidal ideation. Furthermore, the beneficial effects of physical exercise warrant greater emphasis, given its potential to alleviate depressive symptoms and counteract the adverse influence of poor sleep quality on suicidal ideation.