Impact of problematic mobile phone use and insufficient physical activity on depression symptoms: a college-based follow-up study

BACKGROUND: Insufficient physical activity (IPA) and mobile phone dependence are common coexisting behaviors among college students. However, the impact of the synergies between the two behaviors on depression has yet to be validated. Therefore, this study evaluated independent and interactive associations of problematic mobile phone use (PMPU) and IPA with depression symptoms and increased depressive symptoms among Chinese college students. METHODS: In total, 2134 college students participated in this follow-up study, which was conducted between June 2014 (wave 1) and December 2014 (wave 2) at Anhui Medical University. The Self-rating Questionnaire for Adolescent Problematic Mobile Phone Use and the Center for Epidemiologic Studies Depression Scale were used to assess PMPU and depression symptoms, respectively. Physical activity (PA) was assessed with a reliable question from the Youth Risk Behavior Survey. Joint effects of PMPU and PA were calculated, and increased depressive symptoms were assessed. We used multivariable-adjusted odds ratios (OR) with 95% confidence intervals (CI) to evaluate associations between depression symptoms and PMPU, IPA, and the PMPU/IPA joint effect, estimated by binary logistic regression models. RESULTS: PMPU and high PMPU/IPA joint effect scores were significantly associated with depression symptoms in waves 1 (OR 7.36, 95% CI: 5.09, 10.66) and 2 (OR 3.74, 95% CI: 2.56, 5.48). IPA was significantly associated with depression symptoms in wave 1 (OR 1.40, 95% CI: 1.09, 1.79) but not wave 2 (OR 1.24, 95% CI: 0.95, 1.62). PMPU and high PMPU/IPA joint effect scores were also significantly associated with increased depressive symptoms (OR 2.36, 95% CI: 1.55, 3.60). CONCLUSIONS: These results suggest that PMPU is an important factor for depression in college students, and IPA may be a synergistic factor.