I think many people with untreated ADHD may subconsciously self-medicate with caffeine. However, my pdoc said that a stimulant medication- even a low dose- would be the equivalent of 20 cups of coffee in terms of how much stimulant it gives you. So I'm not sure if a couple cups of coffee during the day would have such a drastic effect on your ability to focus. But I could be wrong. Like always, it's best to talk to a professional.