Purpose -The purpose of this paper is to investigate the interrelationships between internet connectedness, online gaming, internet addiction symptoms, and academic performance decrement among the internet-dependent young people in China. Design/methodology/approach -A paper-based survey was conducted among the young clients in one of the earliest and largest internet addiction clinics in China. A total of 594 in-patients (mean age ¼ 17.76 y) voluntarily participated in this study. Findings -By adopting the concept of internet connectedness, this study explored the internet use patterns among the young internet addicts, for example, internet café patrons and those who use internet with more goals or higher degree of internet adhesiveness had more internet addiction symptoms. Online gaming was found to play a significant role in the development of internet addiction. As expected, the level of internet addiction is significantly linked to academic performance decrement. Consistent with previous studies, males showed higher degree of internet connectedness and online game usage than females. Noticeably, the moderation effect of online game playing and the mediating effect of internet addiction were also tested. Research limitations/implications -This research is focussed on the internet-dependent group, thus the generalizability of the results need to be interpreted with caution. Practical implications -This study provides insight for parents, educators, health professionals, and policy makers regarding treatment and intervention for internet addiction among young people in China. Originality/value -Since very little research has been done focussing on diagnosed internet-dependent group, this paper scores as a pioneering study of its kind in China.