What do you do when someone goes back to their old personality?

First of all, of course, I'll try to offer my help to them. Sadly in most cases, we tend to act stubborn, we just won't accept any help from others, because we don't want to seem weak in the eyes of others or just think that what we're doing is right and "couldn't hurt us". We usually think that way until it's too late and that's one of the worst sides of human nature. Sad, but undeniably true. Anyway, I wouldn't give up on a person just because they made a few bad decisions. We all make them and I'm willing to forgive in most cases. But if the other person doesn't wish to go back to his "clean" personality, who am I to stop him? No matter how much I try to change him, it will never work, until he realizes what's good for him on his own.

I will try to confront the person. Good communication may solved the problem. I will tell the person that the old habit is bad especially if it is vices. I can ask also the closest person to advice or tell his friend to stop the things he have already overcome. In that way, maybe we can help him realize that it is not good to continue bad habits.

That is a tough question. Although, it is the person that has to deal with it, friends and families are required to be more patient. While the struggle is much more harder this time being failure the first time, people around them should make extra effort to help. While it is hard on the friends and family looking at their love one fails, imagine how much more harder it is for the person.

I have seen many people changing their lives correctly. Rehabilitation isn`t possible without changing all life. You cannot build something good on old fundament. Sometimes you need just to wake up. When you see somebody to return to all these bad habbits - they was only pretending to be better not living this better life!