I was under the impression that a certain slang version of demon was well known. Then I did a bit of research around the web and noticed urban dictionary, Webster 1913 (as well as this entire node), and other dictionaries also omit this version of the word, which I've heard and used without ever being misunderstood all through my childhood.
Briefly, a demon is a depressing personal, possibly dishonorable memory, which causes you to respond to it for a long and indefinite period in either a radical or suppressive manner. A good example in how you'd hear a conversation about a demon, from beginning to end, is:
"Hey Chuck, what's with your friend? Why's he so angry all the sudden? It's just a game of football."
"He's got a demon."
It's usually considered foul and rude to ask a person about their demon(s). You could say demons are different than suppressive memories in that demons are handled by individuals in ways considered "masculine". You almost don't even take pity on a person for their demons, instead you respect them, and that's that.
Yes, this all is reflective of the whole tough-guy attitude found in sports, gangs, war, and chivalry, but female and non-masculine males can also possess demons- they just have to be of the same quality and spirit. Things that may cause demons:
- Your great failure - War; leaving your friends under fire in cowardice, sports; losing the most important game for your entire team. Usually the failure is something that not only affects you, but there are also exceptions where a personal failure occurs in something you're very passionate and investing with.
- Your horrible action - Gang life/chivalry; rape or murder, backstabbing your friends in a way that changes their life. Hurting one or more people deeply, followed by great empathy and guilt. "What the hell did I do? What the hell did I do?"
- A tragic accident - Something happening to someone you love, or yourself. It's not odd for these kinds of demons to plague with the feeling you could have done something, over and over and over...
- A tragic action - Usually, someone you love committing suicide. Where I'm from, I know very few people who do not have this kind of a demon.
"Demon" is not the word you use when you are talking about the problems you're seeing a psychiatrist for. This sort of thing is not the normal for urban culture. The two absolutes are depression and obsession. That's what makes the word demon worthy of mention; it's the cause and the reply. It's not a demon unless you handle it a certain way (not to say a person's problems are not worthy of the empathy demons recieve- these are just the paramaters for this particular word held by the state of mind that employs it).
Now, there is good news to all this. If demons don't push you into depression, they put you in the perfect mindset to attack your problem. A demon could make a gangster go to Harvard, a bad high school wrestler college champion, a platoon sergeant petition for their war's memorial, or a victim of rape start a coalition to stop it. That's what makes a demon a demon; the noble response.
I'd very much like to tell you that going into depression because of a demon is not noble, but that's not true. Using your demon to fight for good instead of going repressive is forever cooler, but depression is respected in urban culture too. The Japanese also thought like this.