01:19 PM ET 04.10 | NFL players using Adderall has been a prevalent topic in recent months, and according to Seattle's Richard Sherman, more than a few players are taking the attention deficit hyperactivity disorder medication. "About half the league takes it, and the league has to allow it," Sherman said, via the Vancouver Sun. "The league made a mistake in my case. Obviously, I didn't do anything, but you have to go through a process to prove you didn't do anything." Sherman tested positive for a banned substance last season, with a number of reports indicating the drug was Adderall. He successfully appealed his four-game suspension due to a mishandled sample. Sherman, however, wasn't the only player to reportedly fail a drug test due to Adderall use. Brandon Browner, Eric Wright and Aqib Talib have all been suspended for violations of the league's policy on performance-enhancing substances with reports indicating all three failed due to Adderall use.