London: Excessive internet use is likely to contribute to the development of school burnout, which may, in turn, increase digital addiction in adolescents, new research reveals. Burnout is a condition of exhaustion of physical or emotional strength or motivation as a result of prolonged stress or frustration. The findings showed that as a result of school burnout, adolescents' excessive internet use could ultimately lead them to depression. Exposure to digital addiction is most likely to happen if the adolescent loses interest in school and feels cynicism towards school, the researchers said. Also, depressive symptoms and school burnout in late adolescence were found to be more common among girls than boys. Boys suffer more from excessive internet use than girls. The most critical stage for tackling the problem of digital addiction and school burnout is age 13-15. Promoting more activity in school, building up students' motivation to learn can prevent school burnout as well as support adolescents' mental health and avert excessive internet use, the researchers suggested in the paper published in the Journal of Youth and Adolescence. The study -- Mind the Gap -- is a longitudinal research project funded by the Academy of Finland, explored the reciprocal associations between excessive Internet use, school engagement, school burnout and depression among adolescents. The researchers carried out a longitudinal research in more than 3,000 Helsinki adolescents aged 12-14 and 16-18. The former group of early adolescents consisted of lower-school 6th graders born in 2000. The late adolescents were first-year upper secondary school students born in 1997.