This paper presents the second year follow-up research on Internet addiction among Taiwanese high school students from surveys of 753 students. A psychological profile of users was determined in order to differentiate motivation of Internet dependence and non-dependence. Data was analyzed to establish whether sensation seeking was a part of adolescents' excessive use of the Internet. Results indicated that Internet dependents spent more time online (about 20 hours per week) than non-dependents. While Internet dependents perceived significantly more negative Internet influences on daily routines, school performance, and parental relations than non-dependents, both users viewed Internet use as enhancing peer relations. Making friends through the Internet has become a popular activity among adolescents, potentially leading to its excessive use. Internet dependents scored significantly higher on overall sensation seeking and disinhibition than Internet non-dependents. However, the groups did not differ in the life-experience-seeking subscale and thrill- and adventure-seeking-subscales. This finding contradicts that of Lavin et al. (2000), where Internet dependents obtained lower scores on thrill and adventure seeking than Internet non-dependents. Two factors may contribute to the differences in Lavin's study: (1) university students in later adolescence were surveyed; and (2) the students were from a different culture (United States). (Contains 5 tables and 34 references.) (JDM)