Caffeine is good for creative workers, whereas stimulants like Adderall do not necessarily help.
Caffeine also blocks adenosine receptors in your brain. Stephen Braun, author of Buzz: The Science and Lore of Alcohol and Caffeine, once explained it as an “indirect stimulant, as opposed to, say, amphetamine which liberates dopamine, a directly stimulating neurotransmitter. By blocking adenosine receptors, caffeine allows the brain’s own stimulating neurotransmitters (i.e. glutamate and dopamine) to do their thing with greater gusto and less restraint.”
For a time in college I did experiment with a combination of coffee and the now-obsolete tranquilizer Meprobamate (a/k/a Miltown).* Two inches off the floor and flying steady. It’s a good thing that I was too poor to get seriously into that kind of thing.
* People calling Milwaukee “Mil-town” are too young to get the joke?