A *very* long time. Probably since birth if I really think about it. I've never been really under a large pressure to seriously get things done (without major help from my parents) until I was in about 8th-9th grade. This is when I became aware of the problem, and it's only gotten worse and worse over time (I am 22 and a super-senior in college now; the problem is part of the need for the fifth year, though a large part was also physical health). Perhaps my parents didn't give me enough responsibilities around the house, or I just didn't have enough learning to do in elementary school, I don't know.

I have two vivid early memories of ADD evidence (though there were many more that I don't remember). In first grade one time, my teacher was reading a story or something, and all of a sudden she says "DISH (in place of my real name), don't *even* think it!" I hadn't a clue as to why she said it, but she saw my mind work before I even know what was going on... A minute later, I heard something rustle near the door and turned to look and she says "That's it, go over to the desk and put your head down, cover your eyes." First grade me didn't understand and was ready to cry until she said about five minutes later she said, "Feel free to come back when you're ready to pay attention."

Another memory was in fifth grade. I was sitting in science class, and the teacher is talking about something having to do with some sort of chemistry, and I became aware that 15-20 minutes had passed and I hadn't heard a single word (but I was definitely still awake and heard noise). This was the most vivid because I distinctly noticed it and freaked a little. Other cases have happened for shorter periods of time. I can even be carrying a conversation with my girlfriend, and miss a line of what she said, and it gets really frustrating for her.

I hope this helps add a little more detail on when this started and more things that happen.