Over the years Michael Phelps, the most decorated Olympian in history, has used his voice to become a prominent advocate for mental health.

The legendary swimmer recently spoke at the Kennedy Forum's annual mental health conference in Chicago to open up about his struggle with depression and anxiety, CNN reported.

In the 20-minute interview with political strategist David Axelrod, Phelps discussed everything from his post-Olympics depression to the moment he sought help, revealing he's struggled with suicidal thoughts in the past.

Phelps noted that his first depression spell took place in 2004, the same year he was sentenced for a DUI.

"Really, after every Olympics I think I fell into a major state of depression," said Phelps. "After 2012 that was probably the hardest fall for me. I didn't want to be in the sport anymore." Phelps explained that a year later he found himself battling suicidal thoughts.

"I didn't want to be alive anymore," he said. "I'll never forget being in my bedroom at home, literally sitting in there for three to five days just not wanting to be alive."

Find out more about Michael Phelps mental health struggles by Nicole Gallucci at Mashable