Washington Redskins cornerback Cedric Griffin was suspended for a positive test involving the use of Adderall, according to a person with knowledge of the case.

The NFL announced the suspension Tuesday, saying the seven-year veteran had tested positive for a banned performance-enhancing substance; it did not reveal further details because of the confidentiality of the testing program.

Adderall is a stimulant widely prescribed to patients with attention deficit disorder and attention deficit hyperactivity disorder. It increases concentration for those with ADD/HD. To others, it also provides a boost in energy.

Approximately 10 other NFL players have been reported to have been suspended this season for the use of Adderall.

“I would suspect there are people in my business, people in your business who use it,” said Charles Yesalis, a professor emeritus of health policy and administration, and exercise and sport science, at Penn State University. “Anecdotally there’s a lot of evidence that it improves your ability to concentrate. Whether it does that, I don’t know. But if you assume that these people who are using it know something, it clearly should be no surprise that athletes are using this.”

The Washington Post’s Jason Reid, LaVar Arrington, and Dan Steinberg debate whether the Redskins or Giants are more likely to win the NFC East following the Redskins’ victory over the first-place Giants on Monday Night Football. (The Washington Post)

Yesalis said in a telephone interview he’s not certain how effective Adderall is as a performance enhancer in football.

Griffin’s suspension is without pay and runs through the conclusion of the regular season. He would be eligible to return to the team for the playoffs if the Redskins qualify for the postseason. His locker at Redskins Park was cleaned out Wednesday and his jersey No. 20 was given to new practice-squad cornerback Korey Lindsey.

“He’s gone for four games and you make a decision afterwards as to whether he’ll be a part of your football team,” Coach Mike Shanahan said.

Shanahan said he likes Griffin but believes that Griffin made a bad decision.

Redskins cornerback DeAngelo Hall called Griffin’s suspension “absolutely disappointing.”

Said Hall: “There’s nothing I can do about it. I can’t sit there and monitor him or anybody else in this locker room, just like nobody else can. He’ll probably have to deal with those consequences and like I said, we’ll keep fighting. We’ll keep trying to go out there and put the best guys out there on the field and keep trying to get better.”

Two Redskins players, left tackle Trent Williams and tight end Fred Davis, were suspended for the final four games of last season for violating the league’s substance abuse policy, reportedly for testing positive for marijuana. Safety Tanard Jackson has been suspended all of this season for a violation of the substance abuse policy.

“I think you have to look at each situation a little bit differently,” Shanahan said. “If I could talk about this situation, I’d go into detail. But we have a lot of good people on our football team. We talked about Fred’s situation in detail. We talked about Trent’s situation in detail. I feel good about both those guys. Guys have made poor decisions before, but I like our football team and I like where we’re at. A couple of situations, guys have made poor decisions and hopefully we’ll learn from it.”