The prescription drug I take for my ADHD.
Widely abused as a recreational drug. They're known on the street as Fatty Addy, A.D., Study Buddies, Ralls, Headlight Through Fog, Smart Pills, Beenies, Amps, A-Bombs, Addies, Poopy, Blue Buddies, Blue Betties, Orange Tic-Tacs (name used for the higher-dosage orange versions), Blue Dutchman, Candy, A Candy, Blue Boy, Jollies, Smurfs, Rinky Dink, Diet Coke, Davies (for their founder, Dave Herrington), Team Blue, Derallo, The A Train, A+ (in reference to its stimulant effect -- Ambien is often referred to as "A-", the reverse effect of Adderall). In some regions of the U.S. they are known as Railguns and "That'da Boy(s)" (from noted increase in productivity).
On some college campuses taking Adderall is known as Taking the A-Train, most likely inspired by the song "Take The A Train" by Duke Ellington. The 5 and 10 mg doses are also known in the northwest as "BBs", which is short for "Blueberries", named for their blue color. Heavier users tend to use the term "GBs", short for "goof balls". Some Adderall abusers crush and insufflate the 5 and 10 mg. pills, to experience a stronger "rush" and a more rapid onset of the drug's effects. This has led to the term "Smurf Snot," used to describe how the pills color one's mucus blue.