My understanding from my American friends and partner is that it's exactly the same in the USA. Students, software developers, people in finance - for all of them stimulants are normal. I think most people aren't really concerned about being safe - the assumption is that because everyone else is doing it and nobody is getting hurt, it's safe. Which is mostly true (the jury is still out on the long term effects, but for pharmaceuticals the risk is miniscule with normal dosages).
Edit - I will say though that Adderall and coke are by far the most common for people from the USA. For whatever reason those are definitely the North American drugs of choice in my sample.
Edit - I will say though that Adderall and coke are by far the most common for people from the USA. For whatever reason those are definitely the North American drugs of choice in my sample.