hi and welcome! first of all i'd like to say how extremely blessed your brother is to have such a caring family! you all are wonderful...to notice it, but to offer to help in any way necessary is, well simply wonderful.

that being said, i would like to ask if this behavior has been going on for a while? it seems, by your post, that this has only begun to happen recently? if so, it could be due to some life changes he's having and the frustration is coming out at the only place where he feels loved and accepted unconditionally and therefore is "taking it out" on those ppl.

alot of times children, adult and minor, will do that with parents and siblings. they can't take out their frustrations with work and life there, so they take it out on those they know will still accept and love them when they're finished.

what concerns me as well is the fact that he seems to be isolating himself...even in the comfort of home. i wonder if he's isolating in order to escape feelings or events going on in his life right now?

i think you all are definitely doing the right thing by suggesting he see someone! lovingly point out the concerns that there are for him and gently relay them. write them down if necessary. i hope he listens and sees someone. he doesn't sound happy

be safe and let us know?