Agent Dave Davies has said that former boxer Frank Bruno "will be back" after he was admitted to hospital on Friday.
The 53-year-old has had bipolar disorder for 12 years and sought medical assistance after a "severe bout of depression".
"Frank has asked me to thank you for all your kind messages, he says as a boxer he will be back – this is just another fight," Davies said in a statement.
"I'd like to wish Frank well. I know that he's a fighter – he's proved to people over the years that he's a warrior.
"He had three world title challenges that were unsuccessful where a lot of people would have thrown in the towel and quit, but he came back and he made his lifelong ambition of becoming a heavyweight champion a reality."
Bruno won the WBC heavyweight title in 1995.