The suspension of the 2002 American League MVP is effective immediately, the Office of the Commissoner announced Saturday.
"I admitted I made a mistake. But I want people to understand one thing: I wasn't using a drug to take advantage on the field, or be stronger or hit more home runs," Tejada said to Enrique Rojas of ESPNdeportes.com from his home in Florida.
"I've been using it [Adderall] for the past five years and had medical permission from MLB. But my last permit expired on April 15 and they didn't gave me another. I knew that I was in risk of breaking the rules, but at the same time, I could not stop using the medicine because I suffer from ADD [Attention Deficit Disorder]. It's not a vice, it is a disease."
Tejada had previously tested positive under the league's amphetamine policy, so he was subject to a 25-game ban for a second test and an 80-game suspension for a third, both of which occurred while playing for the Royals this season.
"It doesn't matter if you're MVP or king of the world. If you're going to do things that are illegal, you're going to get caught for it and you're going to get suspended," Royals pitcher James Shields said. "It's a shame because I really like him a lot as a teammate."
Tejada's ban is the third-longest non-lifetime suspension handed down by MLB, behind Alex Rodriguez's pending 211-game ban and Steve Howe's 119-game sanction in 1992. He also is the third former MVP to be suspended this season under baseball's drug program, joining Rodriguez and Ryan Braun (65 games) of the Milwaukee Brewers.
Yahoo Sports! reported Tejada's suspension comes after the 39-year-old twice tested positive for Adderall.
"It is unfortunate for me that things have not gone well, but I want people to be clear about my condition, which affects many other people in the world. When I do not take my medicine, I cannot focus properly, and even forget things very easily," Tejada said.
Tejada, who signed a one-year deal with the Royals last offseason, will begin serving the suspension while on the 60-day disabled list with a strained calf muscle. He would need to fulfill the remainder of the suspension next season before he's eligible to play.
Tejada was hitting .288 with three homers and 20 RBIs in 53 games before getting hurt.
Despite the punishment, Tejada said he did not plan to retire from baseball, and will try to get a contract for next year.
"I hope to get the contract, and if possible, the renewal of my permission to use a drug which I depend less each time," he said.
Tejada hurt his calf last Saturday while diving for a ball in the seventh inning of a loss to the Red Sox. He wound up on the DL, and was transferred to the 60-day disabled list -- effectively ending his season -- when the Royals acquired utility man Emilio Bonifacio earlier this week.
"He definitely played well," Shields said. "I've faced him for many, many years and he's one of the best situational hitters that I've ever seen. I never really knew him. To know how he was a teammate and as a player? He was phenomenal."
In 2009, Tejada became the first high-profile player convicted of a crime stemming from baseball's steroids era when he plead guilty to misleading Congress about the use of performance-enhancing drugs.
Under a plea agreement with the same prosecutors that pursued a perjury indictment against Roger Clemens, Tejada admitted he withheld information about an ex-teammate's use of steroids and human growth hormone when questioned by a House committee's investigators in August 2005.
Tejada, a six-time All-Star, also previously acknowledged he bought HGH while playing for the Oakland Athletics, but said he threw the drugs away without using them.
Information from ESPNdeportes.com's Enrique Rojas and The Associated Press was used in this report.