In my opinion a thief is a thief. People don't steal because their HIGH, they don't only steal from stores and in this game very few and far between will you meet someone that wants to help you. Your character is your character. Your belief system is what shapes your principles, morals, values etc. PEOPLE DON'T STEAL BECAUSE THEIR HIGH, THEY STEAL BECAUSE THAT MORAL IS ALREADY IN THEM IT IS ALREADY A PART OF THEIR BELIEF SYSTEM! When they are high they just are more abrasive/brave, its what they want to do and when high versus sober its what they are willing to do.
Just like Boosters that "only" steal from stores. It is virtually impossible for a person to keep this value in place simply because it boils down to them becoming accustomed to taking what they want and/or having what they want. So at some point your shiny item a top of your dresser if they like it, want it and feel they are entitled to it THEY WILL TAKE IT.
Our behaviors over a period of time affect our moral compass, behaviors don't change our compass they regulate the belief in what is right or wrong. Morals, Values and Principles are all part of our belief system of how we view ourselves and the world around us, and all that makes us WHO WE ARE AND IT ALL BEGINS AT BIRTH.
So a thief is a thief and has always had that PRINCIPLE in them. Can they change YES but it takes more than just a drug to do that. SO NO EXCUSES YOU ARE WHAT YOU DO PEOPLE!