Are Mental Health Effects of Internet Use Attributable to the Web-Based Content or Perceived Consequences of Usage? A Longitudinal Study of European Adolescents

Sebastian Hökby   ¹ , MSc ;   Gergö Hadlaczky   ¹ , PhD ;   Joakim Westerlund   ² , PhD ;   Danuta Wasserman   ¹ , MD, PhD ;   Judit Balazs   ^{3, 4} , MD ;   Arunas Germanavicius   ⁵ , MD, PhD ;   Núria Machín   ⁶ , MSc ;   Gergely Meszaros   ^{3, 7} , PhD ;   Marco Sarchiapone   ^{8, 9} , MD, PhD ;   Airi Värnik   ^{10, 11} , MD, PhD ;   Peeter Varnik   ^{10, 11} , PhD ;   Michael Westerlund   ¹² , PhD ;   Vladimir Carli   ¹ , MD, PhD

¹ National Centre for Suicide Research and Prevention of Mental Ill-Health, Department of Learning, Informatics, Management and Ethics, Karolinska Institutet, Stockholm, Sweden

² Department of Psychology, Stockholm University, Stockholm, Sweden

³ Vadaskert Child Psychiatry Hospital and Outpatient Clinic, Budapest, Hungary

⁴ Institute of Psychology, Eötövös Loránd University, Budapest, Hungary

⁵ Clinic of Psychiatry, Faculty of Medicine, Vilnius University, Vilnius, Lithuania

⁶ Skylark Health Research Ltd, London, United Kingdom

⁷ Semmelweis University School of Ph.D. Studies, Budapest, Hungary

⁸ Department of Medicine and Health Science, University of Molise, Campobasso, Italy

⁹ National Institute for Health, Migration and Poverty, Rome, Italy

¹⁰ Estonian-Swedish Mental Health and Suicidology Institute, Tallinn, Estonia

¹¹ Tallinn University, Tallinn, Estonia

¹² Department of Media Studies, Stockholm University, Stockholm, Sweden