?how am i supposed to make him the happy guy he can be?

i have a mate. aquintance more like, we talk now and again, have some sessions etc. ill get to the point, in my eyes he has serious problems.
he cuts himself with razors carving names and poems into his chest, he claims he doesnt feel pain. He drinks every night and before school and if he hasnt he has a break down at school, he's minging in various drugs now and it trying cocain tonight. He is also utterly love sick, when he breaks up with a girl he cries none stop, and the only way to get over them is to get overly obsessed with another..
how am i supposed to make him the happy guy he can be? hes a really good person, but this year all the above happened. He also talks to himself and sits there stares at the wall and laughs at nothing.. could this just be attention seeking?

help!