title: Latent class analysis on internet and smartphone addiction in college students.
abstract: OBJECTIVE
  This study aimed to classify distinct subgroups of people who use both smartphone and the internet based on addiction severity levels. Additionally, how the classified groups differed in terms of sex and psychosocial traits was examined.
  
  
  METHODS
  A total of 448 university students (178 males and 270 females) in Korea participated. The participants were given a set of questionnaires examining the severity of their internet and smartphone addictions, their mood, their anxiety, and their personality. Latent class analysis and ANOVA (analysis of variance) were the statistical methods used.
  
  
  RESULTS
  Significant differences between males and females were found for most of the variables (all <0.05). Specifically, in terms of internet usage, males were more addicted than females (P<0.05); however, regarding smartphone, this pattern was reversed (P<0.001). Due to these observed differences, classifications of the subjects into subgroups based on internet and smartphone addiction were performed separately for each sex. Each sex showed clear patterns with the three-class model based on likelihood level of internet and smartphone addiction (P<0.001). A common trend for psychosocial trait factors was found for both sexes: anxiety levels and neurotic personality traits increased with addiction severity levels (all P<0.001). However, Lie dimension was inversely related to the addiction severity levels (all P<0.01).
  
  
  CONCLUSIONS
  Through the latent classification process, this study identified three distinct internet and smartphone user groups in each sex. Moreover, psychosocial traits that differed in terms of addiction severity levels were also examined. It is expected that these results should aid the understanding of traits of internet and smartphone addiction and facilitate further study in this field.
authors.affiliation: Eulji Addiction Institute, Eulji University, Seoul, South Korea.
authors.forename: Jung-Yeon
authors.initials: JY
authors.lastname: Mok
authors.affiliation: Eulji Addiction Institute, Eulji University, Seoul, South Korea ; Department of Psychiatry, Gangnam Eulji Hospital, Eulji University, Seoul, South Korea.
authors.forename: Sam-Wook
authors.initials: SW
authors.lastname: Choi
authors.affiliation: Department of Psychiatry, Seoul St Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul, South Korea.
authors.forename: Dai-Jin
authors.initials: DJ
authors.lastname: Kim
authors.affiliation: Department of Psychiatry, SMG-SNU Boramae Medical Center, Seoul, South Korea.
authors.forename: Jung-Seok
authors.initials: JS
authors.lastname: Choi
authors.affiliation: Department of Psychiatry, Gangnam Eulji Hospital, Eulji University, Seoul, South Korea.
authors.forename: Jaewon
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Electrical and Information Engineering, SeoulTech, Seoul, South Korea.
authors.forename: Heejune
authors.initials: H
authors.lastname: Ahn
authors.affiliation: Department of Social Welfare, Dongshin University, Naju, South Korea.
authors.forename: Eun-Jeung
authors.initials: EJ
authors.lastname: Choi
authors.affiliation: Department of Counseling and Psychotherapy, Konyang University, Nonsan, South Korea.
authors.forename: Won-Young
authors.initials: WY
authors.lastname: Song
keywords: Eysenck personality type; psychosocial traits; sex difference