Beijing gold medallist Matthew Mitcham has revealed he battled a methamphetamine addiction in 2011 that almost ended his career and destroyed his life.
The Australian 10-metre platform diver who was one of the stars of the 2008 Games, failed to make the final 12 at the London Olympics earlier this year.
In his new book to be released on Monday titled "Twists and Turns," Mitcham opens up about the dark secrets which have shadowed his career.
The 24-year-old said he'd battled low self-esteem, anxiety, depression and panic attacks and had resorted to self-harm as a teenager.
He also admitted to binge drinking and taking recreational drugs, before temporarily quitting the sport in 2006.
Mitcham said he spiralled out of control with crystal meth, after becoming upset over being ranked No.2 in the world, even after his Beijing success.
"I had still failed to achieve my childhood dream of becoming the best in the world at something," said Mitcham.
The Queenslander said he turned to crystal meth to boost his moods.
"Taking it was something I did ... to take my mind off things that were upsetting me - to make me feel better about myself."