Kashi has an addiction history so it is always in the back of my mind. If he does slip into it again (he has not since I have known him) then I would say that I noticed that he seemed unwell or different. If he relapsed I would hope i would have the strength to walk away until he was clean again.

It would be reasonable to worry if your t has a problem whether illness or addiction. You can ask in a caring and concerned way as others have said.