The International Tennis Federation says it's "surprised and disappointed" by Andre Agassi's bombshell admission that he once used crystal meth.

Agassi admits in his new book Open that he used crystal meth for a full year in 1997, which included the first six months of his high-profile marriage to Brook Shields. 

"...I get high a lot. Apart from the buzz of getting high, I get an undeniable satisfaction from harming myself and shortening my career," wrote Agassi.  

Agassi is on the cover of the new People magazine, out Friday.
 
Joey Bartolomeau from People magazine says, "When Andre Agasse was engaged to Brooke Shields he was under a lot of stress and his assistant offered him crystal meth to help him feel better."

Agassi reveals he also lied to tennis officials after failing a drug test. After Agassi failed the drug test he says he never touched crystal meth again. His rocky marriage to Shields ended in 1999 after only two years.

Agassi retired from tennis in 2006 and lives in Las Vegas with his wife, former tennis star Steffi Graf, and their two kids.