title: Mental Health Changes and Its Predictors in Adolescents using the Path Analytic Model: A 7-Year Observational Study.
abstract: OBJECTIVE
  This 7-year observational study examines the hours of TV-watching, phone conversation with friends, using the internet, and physical activity as predictors of mental health among adolescents in south of Iran.
  
  
  METHODS
  At the baseline (in 2005), the participants were 2584 high school students in the 9th to 11th grade. At the baseline, 30% of the available participants (n = 775) were selected in the follow-up (2012) using convenience sampling method. This study used the path analysis to examine the predictors of mental health and to obtain direct, indirect and total effects of the independent variables.
  
  
  RESULTS
  At the baseline (2005), female gender, internet use, maternal education, physical activity and father's education were associated with mental health (p<0.05). Baseline mental health, internet use and physical activity predicted mental health of the participants in the follow up (p<0.05).
  
  
  CONCLUSIONS
  The findings of the study revealed that better mental health in later life is associated with better mental health at baseline, male gender, higher physical activity and phone communication with friends, and less use of the internet and TV.
authors.affiliation: Department of Biostatistics & Epidemiology, School of Public Health, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Ali Reza
authors.initials: AR
authors.lastname: Soltanian
authors.affiliation: Section of Healthy heart, the Persian Gulf Health Research Center, Bushehr University of Medical Sciences, Bushehr, Islamic Republic of Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Amiri
authors.affiliation: Department of Psychologic, Bushehr University of Medical Sciences, Bushehr, Iran.
authors.forename: Soudabeh
authors.initials: S
authors.lastname: Namazi
authors.affiliation: Department of Management and Health Care, School of Public Health, Bushehr University of Medical Sciences, Bushehr, Islamic Republic of Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Qaedi
authors.affiliation: Department of Health, Bushehr University of Medical Sciences, Bushehr, Iran.
authors.forename: Gholam Reza
authors.initials: GR
authors.lastname: Kohan
keywords: Mental health; Path analysis; Psychological symptoms; adolescents