Ivan Wolfgang brought up the topic of Internet addiction a summer ago; in the negative as I recall. Given that he will sometimes charge $500 per hour for a consultation, I tend to believe him. (An alpha problem. However, I didn't have to pay him directly since he was talking at one of Gil Levin's computer seminars.)
The topic is still around and data are starting to appear. Kimberly Young, PsyD, from the U of Pitt (Bradford Campus) found 396 "Internet dependent" people and reported on them at American Psychol. Assn. in Chicago. (1) 35% spent their time in Chat Rooms, 28% in multi-users fantasy games. There was not much use for data bases. 20% more women responded than men; and nearly half were homemakers. She concluded that they wanted social support (which sounds like alliances), sexual fulfillment, & the chance to create a "persona," one of those pretend characters you can don while in chat rooms and in games.
It's a small leap to mania, whether subclinical or the official forms and intensities. There's the issue of sleep disruption, reported to be a contributor to manic episodes. (2) There's a high rate of verbal output at times. Kay Jamison ("Touched by Fire") documented the strong relationships between mood disorders and verbal creativity in poets and other writers.
I know one such person, perhaps eligible for "net dependent" status who can write 20 poems in an evening and who connived the phone numbers of and dates with 50 different girls during a 3 month interval. He met at least 4 who were "officially" diagnosed as bipolar and treated with mood stabilizers. These four are the ones he found most fascinating and got to know the best.(3) (He also gets an emotional high and has difficulty sleeping after theoretical discussions about the meaning of life or some new concepts that he's discovered. I can relate to this kid!)
There are, as always a lot of things mixed together. The operant types would argue legitimately that he's on a variable-ratio pay off for his net contacts, reinforced by some very old and very powerful goodies, i.e., novel women. There are the equally vital rewards of exploration and bragging to his friends about the places he saw. Thus, he works the Net a lot because VR schedules of reinforcement always generate high rates of responding.
Nonetheless, my suspicion is that many of these "addicted" friends have one aspect or another of mania and they're speeding through the Net, looking for each other.
1) National Psychologist, Sept/Oct '97
2) "Journal Watch," published by the Mass Medical Society (August 1997, 3(8), p 62) tosses a relevant chip in the "cycles" vs. "event-driven" debate on bipolar disorder. Interpersonal social rhythm therapy resulted, during a year's coaching, in more stable circadian measures in a group of 19 patients, each having at least 3 prior incidents of mania or depression. The other group of 19 had psychotherapy and did not stabilize their living patterns. However, there was no difference in between the groups with respect to mood regulation. (All were taking maintenance medications.) The original reference is Frank E et al. (1997) Inducing lifestyle regularity in recovering bipolar disorder patients: Results from the maintenance therapies in bipolar disorder protocol. Biol. Psychiatry, 41: 1165-73.
3) I cautioned him that his interest in the girls may be on one plane but theirs in him might be considerably more intense, personal, and volatile ... especially as he moved from girl to girl. His high self-esteem let him reassure me that he would not disrupt their lives. The summer passed without incident.