The effects of parent-child relationship, study stress, and mobile phone use on depressive symptoms among Chinese elementary school students: a moderated mediation model - Kong, Yiting; Su, Zhewei; Wang, Rui; Tan, Jianyu; Zhong, Yuancen; Ai, Ming; Wang, Wo; Hong, Su; Zhang, Qi; Kuang, Li (Frontiers in Psychiatry, 2025)