Seven-time snooker world champion Ronnie O'Sullivan admits he lost years of his career due to issues with alcohol and drugs.
The 47-year-old, who was beaten by eventual champion Luca Brecel in the quarter-finals of this year's World Championship, entered rehab in 2000 after being stripped of the Irish Masters title in 1998 having tested positive for cannabis.
And the snooker great has described how difficult he found it to "live clean" and navigate social situations when attempting to change his lifestyle.
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"There are massive gaps," O'Sullivan told the BBC on the day his new book Unbreakable was released.
"I lost six, seven years to drinking and taking cannabis. Then four years of dealing with stuff away from the table which I didn't deal with very well.
"I wasn't focusing on snooker. But I suppose everyone has those problems, but there's 10 years there where I didn't really do much. I didn't practise much, I didn't have the headspace to win."
O'Sullivan went on to explain how he became anxious when trying to socialise with people, noting that he would "run for the corner" when surrounded by lots of people.
"I lost my personality and confidence and needed to take substances just to feel like I could socialise," he said.