I have a different point of view here. I get made fun of at school for stuff I can't help either. I understand how he's feeling. It's so hard to go for help because (yes even at 18) people will make fun of you even more for being a "snitch" on them. For me it hurts that nobody notices/does anything. Maybe if you let him know that he has your full support then he wouldn't feel quite so alone. I know I'm going to sound hypocritical because I won't talk to my psychiatrist about it, but if you get him to talk to an adult about it then maybe something can be done to stop it, especially if they are younger kids they will probably get scared more easily by adults. I wish you and your brother luck and am sorry y'all are having to go through this. If you ever need anything or woukd like to talk feel free to
PM me any time and I'll get back to you ASAP. I know how much it hurts. He doesn't have to try to be tough. Standing up for yourself can be the hardest and "toughest" thing to do sometimes.
Best Wishes!
~SM~