I think it's more of the concept of it: where do you get them, who you're involved with, why you even need to do it in the first place. I agree, sometimes people DO perform the same or a little better, but this isn't something somebody themselves should diagnose. If they're stressed out, there are better coping skills. If you really want a straight answer my dad works in human resources and hires are fires a lot of people.
Habitual drug use doesn't usually come with an elite crowd, unless you're a rich kid in high school. I mean no offense with what I say.