The only thing necessary for an addict to recover is for he or she to decide that they really want to change. If you really want it, anything is possible. There is no such thing as 'he or she tried their best but still relapsed and went into the darkness'. If we truly want it, and not 99.9% but 100%, it will happen. Trust me, if they failed, they didn't really want it. They didn't want to change completely.