“Mr. Kromka said that Mr. Holmes’s “disposition was a little off” and that he could be socially awkward, one of the quieter people in the lab. He spent much of his time immersed in his computer, often participating in role-playing online games.”
http://www.nytimes.com/2012/07/21/us/shooting-at-colorado-theater-showing-batman-movie.html?pagewanted=3
He was living more socially in his on-line fantasy world (as the bad guy) than he was in the real world. As things got tougher for him in the real world, he slipped gradually into the fantasy one. Does that hypothesis make sense to you?
That may happen to a lot of people as things get worse economically.
I think you are touching the iceburg's tip. The economy is indeed an important factor, but so is the feeling of having some control, this is why drinking becomes much more prevalent in statistic nations: getting drunk is one of the only things they can control.
Another factor is the demeaning of maleness, this is so prevalent in our society that it's become unconscious. Just look at guys in commercials: incompetent, dumber than any woman or child, and otherwise a buffoon.
Consider how many boys get drugged because they act like... boys. Consider what happens if you bring up something that is constitutionally-illegal that the government is doing, usually under statute, and how easily dismissed your arguments are. (Obama's eligibility, Fast & Furious, lots of state courts, lots of state governments.)
Games are one of the few places where a guy can be unapologetically competitive; where what he does matters ("I just saved the world!").
We can call that collision a psychotic break. At least, that's what might be happening in his unwired cell right about now.
He'd been better off, if he's actually as intelligent as so many have made him out to be, if he'd spent at least a day in prison, somewhere along the way. That's an intelligence test, if there ever was one.
Intelligent people who spend even a short time in prison do not want to go back.