Adderall is definitely not placebo. Heightened reactions, quicker processing. I've been diagnosed with ADHD though, but I'm sure it'd benefit and give someone without a diagnosis an edge.
If you have ADHD though, it'd be unfair to ban its use since you're neurologically at a disadvantage. Getting a diagnosis wasn't easy either, for me at least.
Took an 8 hour session that tested IQ as well--a neuropsych evaluation. Feels like most psychiatrists/nurse practioners are becoming more reluctant to hand these meds out or over-prescribe.
I remember a study, and there being data on this, that a lot of the types who use adderall/stims without a script in college and other settings are really ADHDers undiagnosed.