Obsessive Compulsive Disorder ... in the easiest way to explain it, there is something in your life that needs to be done a certain way or look a certain way, and if it's not, you will GO CRAZY. We're talking you will literally DIE if it's not fixed or done right.
examples: using one's foot to flush a toilet, knocking on wood three times to ward of a bad omen, throwing salt over one's shoulder for a positive future, or feeling inspired to say "God forbid!" after mentioning the potential death of a living person, "I might get AIDS from the germs on that door knob;" "Since I had the thought of killing my baby, I might be capable of doing it;" "If I don't pick up that Band-Aid someone else might get sick from it, and I would hold myself culpable." etc! It's wild, some people have some crazy ocd's.
So if my OCD is diagnosable, it could be because of my addiction to wanting certain things, like a video game or cellphone. If I don't get it soon I'll start to go crazy, it's all I'll talk about, I'll make references to it somewhere to my parents so it'll get to them and they'll eventually fall through and get me it, I dunno!