I've been involved in WriteOnCon the past week, and while it's been a blast, it has brought back memories of my childhood, when I had a problem with borderline internet addiction.
Spending too much time on the internet and suffering from depression were a sort of perfect storm for me when I was a teenager. I'd go on the internet and escape to chat rooms and forums, getting excited every time I "met" someone and thought we were friends. That's not to say you can't be friends with someone over the internet, but it's a different sort of friendship, and at that age I couldn't tell the difference.
There's a lot of science being done these days about how the internet stimulates the reward centers of our brain, and how there's very little difference (physically) between what happens when you're hooked to the internet and what happens when you're hooked to, say, cocaine.
I think I've grown into a more comfortable place with the internet. I know when I need to avoid it, how much time I can give myself, and where to draw the lines. But it's never easy. You can't spell dopamine without [the cognate] dope.