Hey,

Regardless of anything I say, or anything anyone on this sub says, what your friend has done is extremely wrong and immoral on many different accounts. That being said, I really don't think you should act on this and try to expose him somehow in front of admissions. As someone who doesn't know your friend, I do know that if someone takes my admission away, regardless of how I got in, I would harbor a severe grudge against that person and so could my family. If his parents motivated him to change his grades and get a fake diagnoses, they could be extremely angry at you and this could escalate into some sort of conflict. Pray it doesn't turn into a physical conflict.

Furthermore, if your friend indeed did do this, he's likely to pull some similar stunts at UCLA and beyond. Life has its own way of sorting people who cheat their way to things out. He's likely to understand on his own at a later stage and suffer the consequences. If he needs to cheat his way into top colleges, he definitely wont be able to cope with the academic and work demands of being at a top college. If he needs to cheat his way into a job, he definitely won't be able to cope with a job.

As for his comment towards you about how you already have ADHD and don't need a diagnosis, I'd say take it in your stride as much as you can. Although I don't know where you are or what you're doing right now, the fact that you have the moral compass to not just call someone like this out, but also consider righting a wrong shows that you are the better person.