Background: The present longitudinal study examined predictors of compulsive internet use and depression. Method: Adolescents, 21 males and 20 females, completed online questionnaires with a 12-month interval. Results: Social internet use (i.e., using instant messaging and social networks) was associated with decreased levels of depression. High support satisfaction, use of social networking, and instant messaging contributed to lower changes in compulsive Internet use. Conclusion: The effects of social internet use in combination with different psychosocial factors seem to have more positive effects than negative ones on change in depression and the development of compulsive internet use.