No matter how bad it looks, suicide should NEVER be an option.  I know, I know, when your mind is clouded, it is hard to see that.  But you must impress upon him this.  If he's so desperate, willing to give up his life, then let him declare his life for the goodness of others rather than throw it away for no one to enjoy.  He can REALLY make a difference... just volunteering for something simple, like a soup kitchen, or to help homeless kids...  even if it is a few hours a week.  Get him to redirect his life.  Once he does this for a while, he'll be able to pull back his perspective and see more clearly.  You may be his only hope... too many teen suicides these days.  Teen suicide is the WORST thing, next to outright murder.  To snuff one's own life, even before it has truly begun.  It should NEVER happen!

Good luck...