Ricky Hatton said he was "back to fight for world titles" as he announced his return to boxing.
Hatton, who would often put on weight between fights and checked into a rehabilitation centre in London in 2010 after being photographed apparently snorting cocaine, said:
He said: "It's well documented what's happened to me, my life turned to mush. I feel I've put a bit back into the game but it didn't fill the void. I got my trainer's licence and started working in the ring and that started the fires burning and I started looking after myself a bit better.
"I'm back to fight for world titles. It's more than a comeback. It's worth more than money. A lot of people have said they don't want me to tarnish the legacy but they don't know what goes on between my ears."
More top news
Welsh surgeon David Nott is bringing 25 years of war surgery experience to Syria's beleaguered medical professionals.
A plane was diverted to and forced to land at Glasgow Prestwick airport following a "temporary loss of communication".
More than a third of Britons feel they are not getting enough sleep - the highest figure in the world - according to a study.