Answer:
Bi-Polar Disorder
Explanation:
According to the presented conditions, it is possible that Don is suffering from Bi-Polar Disorder. This is because of his dual personality characteristics exhibition in Don’s daily routines. The details also show that he has some kind of illegal income source that is affecting him in some way. He is depressed because he is in some kind of trouble. That’s the reason he is showing various polarities of his personality
Pelvic inflammatory disease is the most likely cause in 99% of studies on this matter
You could say something along the lines of:
"Hey, Friend, what's so good about weed? Why are you always smoking it?"
If he's smoking it for medical purposes, then just drop it, but if it's illegal and he's doing it to "look cool", then I would further ask questions about it.