NEW YORK -- Andre Agassi used crystal meth periodically for "a year or so," the eight-time Grand Slam champion revealed in an interview with People magazine.

In his upcoming autobiography, Agassi admits he used crystal meth in 1997 and failed a drug test -- a result he says was thrown out after he lied by saying he "unwittingly" took the substance.

"If you're going to tell your story, you owe it to yourself to tell it honestly," Agassi told the magazine in its latest issue. "Especially if you're going to call it 'Open,"