BACKGROUND: With the increasing incidence of mobile phone addiction, mobile phone addiction has been considered to be related to adolescents' psychological distress. However, the underlying mechanisms of this relation were still unclear. The present study tested the mediating role of rumination and the moderating role of the capacity to be alone in the relation between mobile phone addiction and psychological distress. METHODS: 754 middle school students were recruited to complete measures of mobile phone addiction, rumination, the capacity to be alone, psychological distress and demographic v...