The NFL has confidentiality guidelines in place to protect players in case of a failed drug test. It is my belief that they are really just protecting their own image.
Taking adderall as a performance-enhacing drug on the field makes zero sense to me. I've tried it. It enhanced absolutely nothing except my cottonmouth. (Off the field however; in film rooms, may be an entirely different story.)
There is no current format for HGH-testing in the league, and my guess is that at least 40% of the players would be totally screwed if they drew blood samples today.
The NFL doesn't want to end up like the MLB, so they are taking every precaution possible to mask the use of ACTUAL performance-enhancing drugs being used by players right now. This includes allowing players to blame "adderall" to the media. I don't buy it.