Funny to see this posted...I just received this: http://www.latimes.com/business/la-fi-a ... full.story today in a pharmacist newsletter I get weekly. According to that article, I'm addicted . I did a quick literature search and came up with some interesting abstracts:

Grüsser SM, Thalemann R, Albrecht U, Thalemann CN.[Excessive computer usage in adolescents--results of a psychometric evaluation] Wien Klin Wochenschr. 2005 Mar;117(5-6):188-95. (This article is in German)
Excessive computer and video game playing among children is being critically discussed from a pedagogic and public health point of view. To date, no reliable data for this phenomenon in Germany exists. In the present study, the excessive usage of computer and video games is seen as a rewarding behavior which can, due to learning mechanisms, become a prominent and inadequate strategy for children to cope with negative emotions like frustration, uneasiness and fears. In the survey, 323 children ranging in age from 11 to 14 years were asked about their video game playing behavior. Criteria for excessive computer and video game playing were developed in accordance with the criteria for dependency and pathological gambling (DSM-IV, ICD-10). Data show that 9.3% (N = 30) of the children fulfill all criteria for excessive computer and video game playing. Furthermore, these children differ from their class mates with respect to watching television, communication patterns, the ability to concentrate in school lectures and the preferred strategies coping with negative emotions. In accordance with findings in studies about substance-related addiction, data suggest that excessive computer and video game players use their excessive rewarding behavior specifically as an inadequate stress coping strategy.

Rau PL, Peng SY, Yang CC. Time distortion for expert and novice online game players. Cyberpsychol Behav. 2006 Aug;9(4):396-403. (Chinese study)
Online game addiction is a new mental disorder. This disorder is difficult to describe because of its comprehensive nature. Many online game players have problems controlling their playing time. They cannot stop playing a game that they enjoy. This research surveyed the past literature on "flow" and time disorder theory. A time distortion experiment was conducted. This research invited 64 children, teenagers, and young adults to investigate player skill and playing time effects on online game break-off. The playing experience and degree of time distortion were measured and analyzed. The results showed that both novice and expert online game players were subject to time distortion. The participants had difficulty breaking off from the game without intrusion by others in the real world. This research also suggests eight questions for self-evaluation for online game addiction.

Allison SE, von Wahlde L, Shockley T, Gabbard GO. The development of the self in the era of the internet and role-playing fantasy games. Am J Psychiatry. 2006 Mar;163(3):381-5.
http://ajp.psychiatryonline.org.db.usip ... /163/3/381 (Not sure if this link will work for you, if you're interested PM me and I can try to email it to you)

Johansson A, Götestam KG. Problems with computer games without monetary reward: similarity to pathological gambling. Psychol Rep. 2004 Oct;95(2):641-50.
An epidemiological study was performed on a representative sample of the Norwegian youth population (12 to 18 years old, N=3,237; response rate 45.2%). The percentage who were frequent players (weekly) of different computer games was 63.3%, and the percentage of infrequent users was 36.7%. A mean of 2.7% (4.2% of the boys, 1.1% of the girls) could be described as exhibiting "pathological playing" according to the criteria in the 1998 Diagnostic Questionnaire for Internet Addiction of Young, and an additional 9.82% (14.5% of the boys, 5.0% of the girls) were considered to be engaging in "at-risk playing." Of the weekly gamblers, 4.2% fulfilled 5 criteria for pathological playing, and an additional 15.5% 3 to 4 criteria, i.e., at-risk playing. This indicated that frequent gaming on computer games without money rewards may be related to problematic playing even though no monetary reward is involved.