Oy Sis... *hugs* My thoughts are with you. My youngest brother is ADHD (that's what it is in english... you were right, very similar *grin*) and he was a handful for my mom. He was adopted, so he had that burden to deal with on top of everything else... which included anger management problems, learning disabilities, and fetal alcohol syndrome. A very screwed up kid. Eventually the Province had to step in and remove him from our home because he had threatened to kill mom in her sleep... and had hidden the tools to do so.
He's 19 now, I still love him, he's still my brother, but every time one of us has tried to help him, he lies/steals/etc and gets himself right back into trouble. He doesn't want to change his life, but expects us to bail him out every time he gets in trouble. Unfortunately it just doesn't work that way. All I know now, is that he is somewhere in Ontario, since he moves around a lot.
I'm not sure what more you can do, than what you're already doing. I'm assuming he's already on the medication available for adhd, which, while it helped my brother, didn't help with everything. My prayers are with you Sis. *huggers*