I remember myself struggling with Quake 3. It really felt to some extend hypnotic. Only after giving myself a proverbial slap on the face at around 2014 when I was 13 or so, and getting conscious of that being a problem, was I able vent Q3 out of my head.
I was addicted to video games into my 20s. Even now I have urges to fire up some MMO. It was only when I started working in UX design and researched human behavior that I understood how incredibly addictive video games are. Well designed video games go above and beyond to make you keep playing them. Even as a professional designer I frequently look to games to get ideas about how to hook visitors to spend more time in sites and apps. It's very ironic that the system that gamed me (pun intended) is now something I'm actively part of.
The interesting thing about both your examples (Q3 and MMOs) is that both are games with no finish point.
I think that's not a coincidence, and it's not just about games. If you think about it, all forms of entertainment boil down to giving our mind a different world to inhabit for a while. It's pretty obvious with books and movies and theater etc, and with "traditional" games. But in a sense, the gaming board of something like Bejeweled is also a world, just a very simplified one. And stuff like social networks are also a world, the one that's built out of real people, but with its own set of relationships and problems and drama etc. All of this lets your brain "go elsewhere".
But here's the big difference. Some forms of entertainment engage in such world building to tell a story. But a story has its finale - once it is done, you leave the world it inhabits, and come back to reality. You can go back for another take, but the thing about stories is that the second time is not like the first. It's diminishing returns.
With modern - problematic - forms of entertainment, like MMOs and addictive mobile games and social media - the world is intentionally designed to be inhabited permanently. Worse yet, it's designed to be painful to withdraw from, even temporarily. There is no final line - there's no "game over, you won" in a MMO, or a happy (or sad, or any) ending of the Facebook drama. The people who make those things want it that way, because every minute you spend in their world, they can extract rent from you. With stories, you pay per story; here, you pay per hour.
Basically, social media and addictive games are the equivalent of a never-ending soap opera that's on 24/7. Imagine if something like this existed 50 years ago; do you think the effects would have been different? It's just that back then, it was not economically feasible. And now it is; and here we are.
