You will find that many programs will be understanding of that. Use this to your advantage. Show that you have developed healthy coping mechanisms. Reflect how you learned more about yourself through the process. Showing that you are willing to address stressful situations and work through them via healthy means is a great way to impress the ADCOMs. Substance abuse is big problem in anesthesia and healthcare in general. If you have healthy coping mechanisms, you will be that more resistant to it. Anesthesia school is very burdensome and stressful. If you have been in that type of situation before and have already developed the coping skills to work through tough situations, I think you are ahead of the game. I have noticed a different attitude toward mental health in anesthesia school. All of the faculty has focused on self care, healthy outlets, hobbies, time with family, even counseling, etc. I would bring it up and highlight how you have grown.