When I had a doctor, he said I couldn't take meds for my ADD on account of my Wolff-Parkinsons White. I'd like a second opinion from you please.
You need to have consensus between a cardiologist and a psychiatrist about whether medications are appropriate and what type, and an appropriate monitoring plan established that all three of you are on board with and can follow, before taking ADD medications. As a psychiatrist if confronted with that situation I would not prescribe stimulants to someone with known WPW unless/until I could get a letter from the cardiologist.
For God's sake, don't take your friend's Adderall, just yet anyway.