He's 14, as am I.
His parents originally were trying to make a "genius kid" out of him, needless to say after about 14 1/2 years of ADHD medication, intense stress of being sent to a school for gifted children for a few years until he flunked out, and perhaps physical abuse (heard and saw lots of things involving his parents beating him), leaving him with very little social skills, and turning him into a perhaps clinically insane shell of a person with very little personality.I think that explains that his parents don't give two stuffs about him, or his sister (who may or may not be normal).
He only wants to go away from his parents.
That could be so, except for the fact that they work all day.
Get your trusty "not a weapon but will still beat the stuff out of him" blunt object like a toaster and while you're making toast and he comes up behind you spin arund and say "WANT TOAST?"
You should try and teach him social skills, and how not to be annoying.
When ever he comes over, he rings the doorbell until someone answers, or until it starts getting dark. He even looks in the windows and looks for us.