title: Prevalence and correlates of problematic internet experiences and computer-using time: a two-year longitudinal study in korean school children.
abstract: OBJECTIVE
  To measure the prevalence of and factors associated with online inappropriate sexual exposure, cyber-bullying victimisation, and computer-using time in early adolescence.
  
  
  METHODS
  A two-year, prospective school survey was performed with 1,173 children aged 13 at baseline. Data collected included demographic factors, bullying experience, depression, anxiety, coping strategies, self-esteem, psychopathology, attention-deficit hyperactivity disorder symptoms, and school performance. These factors were investigated in relation to problematic Internet experiences and computer-using time at age 15.
  
  
  RESULTS
  The prevalence of online inappropriate sexual exposure, cyber-bullying victimisation, academic-purpose computer overuse, and game-purpose computer overuse was 31.6%, 19.2%, 8.5%, and 21.8%, respectively, at age 15. Having older siblings, more weekly pocket money, depressive symptoms, anxiety symptoms, and passive coping strategy were associated with reported online sexual harassment. Male gender, depressive symptoms, and anxiety symptoms were associated with reported cyber-bullying victimisation. Female gender was associated with academic-purpose computer overuse, while male gender, lower academic level, increased height, and having older siblings were associated with game-purpose computer-overuse.
  
  
  CONCLUSIONS
  Different environmental and psychological factors predicted different aspects of problematic Internet experiences and computer-using time. This knowledge is important for framing public health interventions to educate adolescents about, and prevent, internet-derived problems.
authors.affiliation: Department of Psychiatry, Gangnam Severance Hospital, Seoul, Republic of Korea.
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Yang
authors.affiliation: Institute of Psychiatry, Section of Epidemiology, King's College London, London, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Stewart
authors.affiliation: Department of Psychiatry, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Ju-Yeon
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Psychiatry, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Jae-Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: Department of Psychiatry, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Sung-Wan
authors.initials: SW
authors.lastname: Kim
authors.affiliation: Department of Psychiatry, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Il-Seon
authors.initials: IS
authors.lastname: Shin
authors.affiliation: Department of Psychiatry, Chonnam National University Medical School, Gwangju, Republic of Korea.
authors.forename: Jin-Sang
authors.initials: JS
authors.lastname: Yoon
keywords: Adolescent; Computer overuse; Cyber-bullying; Longitudinal study; Online sexual exposure