Michael Phelps says he thought of taking his own life on numerous occasions at the height of his career.
Phelps – the most decorated Olympic athlete of all time with 23 gold medals – first thought of committing suicide after the Athens 2004 Olympic Games.
The 32-year-old sought professional help after of reaching a "historical minimum" after London 2012.
"After every Olympiad, I think I fell into a great state of depression," Phelps said.
"I remember having treated me the first day, I was shaking because I was sick."
Phelps, who announced his retirement after London 2012 before returning to the sport two years later, said he was he realized the magnitude of his problems after the Games, when he locked himself in his room for "three to five days".
He went on to win five gold and one silver medals in Rio before retiring and said that the emotions of overcoming his mental health problems were much greater than those of winning his Olympic titles.
Speaking at the Kennedy Forum on mental health in Chicago, Phelps added: "Those moments and those feelings and those emotions for me are light years better than winning the Olympic gold medal.
" I am extremely grateful that I did not take my life. "