title: Mobile phone use and stress, sleep disturbances, and symptoms of depression among young adults--a prospective cohort study.
abstract: BACKGROUND
  Because of the quick development and widespread use of mobile phones, and their vast effect on communication and interactions, it is important to study possible negative health effects of mobile phone exposure. The overall aim of this study was to investigate whether there are associations between psychosocial aspects of mobile phone use and mental health symptoms in a prospective cohort of young adults.
  
  
  METHODS
  The study group consisted of young adults 20-24 years old (n = 4156), who responded to a questionnaire at baseline and 1-year follow-up. Mobile phone exposure variables included frequency of use, but also more qualitative variables: demands on availability, perceived stressfulness of accessibility, being awakened at night by the mobile phone, and personal overuse of the mobile phone. Mental health outcomes included current stress, sleep disorders, and symptoms of depression. Prevalence ratios (PRs) were calculated for cross-sectional and prospective associations between exposure variables and mental health outcomes for men and women separately.
  
  
  RESULTS
  There were cross-sectional associations between high compared to low mobile phone use and stress, sleep disturbances, and symptoms of depression for the men and women. When excluding respondents reporting mental health symptoms at baseline, high mobile phone use was associated with sleep disturbances and symptoms of depression for the men and symptoms of depression for the women at 1-year follow-up. All qualitative variables had cross-sectional associations with mental health outcomes. In prospective analysis, overuse was associated with stress and sleep disturbances for women, and high accessibility stress was associated with stress, sleep disturbances, and symptoms of depression for both men and women.
  
  
  CONCLUSIONS
  High frequency of mobile phone use at baseline was a risk factor for mental health outcomes at 1-year follow-up among the young adults. The risk for reporting mental health symptoms at follow-up was greatest among those who had perceived accessibility via mobile phones to be stressful. Public health prevention strategies focusing on attitudes could include information and advice, helping young adults to set limits for their own and others' accessibility.
authors.affiliation: Occupational and Environmental Medicine, Department of Public Health and Community Medicine, University of Gothenburg, Gothenburg, Sweden. sara.thomee@amm.gu.se
authors.forename: Sara
authors.initials: S
authors.lastname: Thomée
authors.forename: Annika
authors.initials: A
authors.lastname: Härenstam
authors.forename: Mats
authors.initials: M
authors.lastname: Hagberg
mesh_terms: D040421:Cell Phone / Q000706:statistics & numerical data*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003863:Depression / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D011446:Prospective Studies; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000453:epidemiology* / Q000209:etiology; D013315:Stress, Psychological / Q000453:epidemiology* / Q000209:etiology; D011795:Surveys and Questionnaires; D013548:Sweden / Q000453:epidemiology; D055815:Young Adult