Since the diagnostic criteria for Internet Use Disorder have not yet been fully established, previous studies on the prevalence of Internet Use Disorder can only be compared to some extent, since diangnostic criteria varied between countries and research groups.
In previous studies prevalence rates of Internet Use Disorder have been estimated to be between 1 and 10%. Further studies are required.
Several studies on the prevalence of Internet Use Disorder reported prevalence rates of about 1.5 to 8% among minors, with higher prevalence rates in minors with a history of other mental health problems.
Johansson and Götestam assessed the prevalence of Internet addiction in a sample of 3237 Norwegian adolescents age 12 -18 (response rate 45.2%). According to the authors about 2% of the adolescents (boys 2.4%, girls 1.5%) could be described as having an Internet addiction (cf. Johansson 2004).
Kaltiala-Heino et al. conducted a survey of 7292 Finns age 12-18 years. About 1.5% of the adolescents fulfilled criteria for an Internet addiction (cf. Kaltiala-Heino 2004).
In a recent article Poli and Agrimi reported on a survey of 2533 Italian students. The majority of respondents (94%) were classified as normal users of the Internet, 5% as moderately addicted and 0.8% as seriously addicted (cf. Poli 2012). In an older Italian study Pallanti et al. reported a rate of Internet addiction of about 5.4% in a sample of 275 Italian students (cf. Pallanti 2006).
Slightly higher rates (8.2%) were reported by Siomos et al. among Greek adolescents age 12 to 18 (cf. Siomos 2008).
Among Iranian high-school students Ghassemzadeh reported rates of Internet addiciton of about 3.8% (cf. Ghassemzadeh 2008).
In a sample of 1573 Korean high-school students Kim et al. diagnosed 1.6 as Internet addicts and 38% as possible Internet addicts (cf. Kim 2006).
In one of the largest surveys so far, Xu et al. assessed the prevalence of Internet addiction in a sample of 5122 Chinese students. 8.8% of the adolescents showed symptoms of Internet Use Disorder (cf. Xu 2012).
Among 81 clients of an adolescent psychiatric institution in Germany between the age of 8 and 17 years, Müller et al. found a prevalence of 11% of comorbid addictive internet use (cf. Müller 2012).