If you read the study it's only tested with 13 people, and the article says that the understanding of the effects on people with out adhd are not understood. In the drug community it is widely used for work to produce a higher work output and you are actually able to focus alot more, I used to work it a fast pace factory for 70 hours a week and I would not have been able to do the work I did without Adderall. Adderall and dextroamphetamine also helped a ton in college I got way better grades when I used it. It doesn't help with complex learning but when it's for focus it's proven to help.