Internet addiction: characteristics of a questionnaire and prevalence in Norwegian youth (12-18 years).

The use of the Internet has increased considerably during the last few years, and there are also some clinical observations that some people 'get hooked', and develop an Internet addiction. An epidemiological study was performed in a representative sample of the Norwegian youth population (N= 3,237; response rate 45.2%). The proportion not using Internet was only 4.9%, while 35.8% were non-frequent users, and 49.6% (1,591) were frequent (weekly) users. They used the Internet on the mean 4.3 hours a week. A mean of 1.98% (boys 2.42%, girls 1.51%) could be described as having an 'Internet addiction' according to the criteria in the Diagnostic Questionnaire of Young (1998), and an additional 8.68% (in sum 10.66) were considered to have an at-risk Internet use (boys 9.21%, girls 8.13%). If these proportions were calculated on individuals who used the Internet frequently, 4.02% fulfilled 5 criteria, and an additional 17.66% 3-4 criteria, giving quite high figures of problematic Internet use (in sum 21.68). The different diagnostic criteria gave a broad range of affirmative answers (from 0.4% to 27.9%). The results have important implications for further studies of prevalence, implementation of preventive measures, and the development of treatment approaches for Internet addiction.