Is there a way to deal with my ADHD brother ?

a) ADHD is not actually a diagnosis, its a made up mental illness for badly behaved kids. My sister is terrible, bloody awful she is and shes 14 and exactly the same, shes not got "ADHD" and b) i think someone really needs to talk to your brother, preferably a man, maybe your dad or boyfriend? Someone who can say to him in a strict firm way. "Look, you cant be like this, you either change or..." you know? someone needs to be really really strict with him and i say a man because men are more scary than women. he needs putting in his place. the sooner the better! Good luck.