With the popularity and wide-spread promotion of the Internet, this study first sought to determine a set of criteria which would define addictive from normal Internet usage. If a workable set of criteria could be effective in diagnosis, then such criteria could be used in clinical treatment settings and facilitate future research on addictive Internet use. However, proper diagnosis is often complicated by the fact that the term addiction is not listed in the Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition (DSM-IV; American Psychiatric Association, 1994). Of all the diagnoses referenced in the DSM-IV, Pathological Gambling was viewed as most akin to the pathological nature of Internet use. By using Pathological Gambling as a model, Internet addiction can be defined as an impulse-control disorder which does not involve an intoxicant. Therefore, this study developed a brief eight-item questionnaire referred to as a Diagnostic Questionnaire (DQ) which modified criteria for pathological gambling to provide a screening instrument for addictive Internet use:

1. Do you feel preoccupied with the Internet (think about previous on-line activity or anticipate next on-line session)?
2. Do you feel the need to use the Internet with increasing amounts of time in order to achieve satisfaction?
3. Have you repeatedly made unsuccessful efforts to control, cut back, or stop Internet use?
4. Do you feel restless, moody, depressed, or irritable when attempting to cut down or stop Internet use?
5. Do you stay on-line longer than originally intended?
6. Have you jeopardized or risked the loss of significant relationship, job, educational or career opportunity because of the Internet?
7. Have you lied to family members, therapist, or others to conceal the extent of involvement with the Internet?
8. Do you use the Internet as a way of escaping from problems or of relieving a dysphoric mood (e.g., feelings of helplessness, guilt, anxiety, depression)?

Respondents who answered "yes" to five or more of the criteria were classified as addicted Internet users (Dependents) and the remainder were classified as normal Internet users (Non-Dependents) for the purposes of this study. The cut off score of "five" was consistent with the number of criteria used for Pathological Gambling. Additionally, there are presently ten criteria for Pathological Gambling, although two were not used for this adaptation as they were viewed non-applicable to Internet usage. Therefore, meeting five of eight rather than ten criteria was hypothesized to be a slightly more rigorous cut off score to differentiate normal from addictive Internet use. It should be noted that while this scale provides a workable measure of Internet addiction, further study is needed to determine its construct validity and clinical utility. It should also be noted that the term Internet is used to denote all types of on-line activity.

METHODOLOGY

Subjects

Participants were volunteers who respondent to: (a) nationally and internationally dispersed newspaper advertisements, (b) flyers posted among local college campuses, (c) postings on electronic support groups geared towards Internet addiction (e.g., the Internet Addiction Support Group, the Webaholics Support Group), and (d) those who searched for keywords "Internet addiction" on popular Web search engines (e.g., Yahoo).

Materials

An exploratory survey consisting of both open-ended and closed-ended questions was constructed for this study that could be administered by telephone interview or electronic collection. The survey administered a Diagnostic Questionnaire (DQ) containing the eight-item classification list. Subjects were then asked such qustions as : (a) how long they have used the Internet, (b) how many hours per week they estimated spending on-line, (c) what types of applications they most utilized, (d) what made these particular applications attractive, (e) what problems, if any, did their Internet use cause in their lives, and (f) to rate any noted problems in terms of mild, moderate, or severe impairment. Lastly, demosgraphic information from each subject such as age, gender, highest educational level achieved, and vocational background were also gathered..

Procedures

Telephone respondents were administered the survey verbally at an arranged interview time. The survey was replicated electronically and existed as a World-Wide-Web (WWW) page implemented on a UNIX-based server which captured the answers into a text file. Electronic answers were sent in a text file directly to the principal investigator’s electronic mailbox for analysis. Respondents who answered "yes" to five or more of the criteria were classified as addicted Internet users for inclusion in this study. A total of 605 surveys in a three month period were collected with 596 valid responses that were classifed from the DQ as 396 Dependents and 100 Non-Dependents. Approximately 55% of the respondents replied via electronic survey method and 45% via telephone survey method. The qualitative data gathered were then subjected to content analysis to identify the range of characteristics, behaviors and attitudes found.