Adderall is generally included under "nootropics", and is a stimulant. Its precursor was Benzedrine, which was used by some names you might recognize: W.H. Auden, James Agee, Graham Greene, Philip K. Dick, John-Paul Sartre, Paul Erdös, Jack Kerouac. The latter wrote "On The Road" in three weeks while under its influence.
http://www.slate.com/articles/health_and_science/medical_exa...