What's wrong with my friend?

Ok so my friend is 17 with a horrid past, he's dealt with a verbally abusive stepdad for six years and his mom doesn't do too much to help, he's dealt with a drunk and druggie and a pedophile, he tells me that women don't give him any chances and thinks love is the ultimate happiness and love equals happiness and he feels like if he has no love he has nothing to live for and he's said he would kill himself or hurt himself, he says he feels isolated. Alone and un loved, I'm really concerned about him, what should I do?