Background: This study investigates the times adolescents engage in different media activities (including entertaining and educational activities) and explores associations with behavioral strengths and difficulties and school grades. Methods: This cross-sectional study included 664 10- to 18-year-old adolescents (350 boys, 314 girls) participating in the LIFE Child study in Germany. Participants completed questionnaires on their media use, on strengths and difficulties (using the Strengths and

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... Difficulties Questionnaire), and on their school grades in mathematics and first language. Associations of the times engaged in different media activities via mobile phone or computer (traditional communication, social media use, gaming, playing learning games, watching videos, and searching for information) with behavioral strengths/difficulties and school grades were assessed using linear regression analyses (adjusting for age, gender, and socioeconomic status). Results: With the exception of playing learning games, each media activity was followed for almost one hour per day, with high inter-relations between the single activities. Gaming, watching videos, social networking, traditional communication, and playing learning games were significantly associated with more behavioral difficulties in at least one domain (emotional problems, conduct problems, hyperactivity/inattention, peer-relationship problems, prosocial behavior) and with lower school grades. Searching for information showed the weakest associations with behavioral difficulties and no association with school grades. In a multivariate analysis, searching for information was associated with fewer behavioral difficulties. Conclusions: Using media to search for information might weaken the adverse effects of other media activities on school performance and behavioral adjustment.