(CNN) It was in 2014, following a second drink driving charge and a six-month suspension from USA Swimming, that Michael Phelps started to talk.
It wasn't easy at first. The 23-time Olympic gold medalist had suffered a downward spiral that had got so bad he confined himself to one room for five days.
But talking has helped and Phelps -- the most decorated Olympian of all time who retired after Rio 2016 -- can now speak openly about his struggle with depression.
"It's a dark, dark road sometimes and you just want to make sure you are staying open," 33-year-old Phelps tells CNN.
"I'm very comfortable talking to my wife, I'm comfortable talking with a therapist ... but in the beginning I wasn't."
It was at the age of 15 that Phelps competed in his first ever Games in Sydney.
He didn't medal then, but went to amass 28 over the course of four Olympics -- 16 in individual events and 12 in relays.
Yet after the glow of competition had faded, Phelps' mental health would start to suffer. It was after London 2012, having announced his first retirement from the sport, that he reached rock bottom.
"There was a part of my life I didn't want to be alive," he says.
If his career has been interspersed with controversies relating to depression, including alcohol abuse and being photographed smoking from a bong and his struggles with depression continue, Phelps is prepared to speak openly about his mental health.
"You know, two to three weeks ago I went through a pretty scary depression spell," said Phelps.
"This is something that's going to continue to happen in my life. But the more I can learn about myself and understand why I'm going through these things."
He credits his wife Nicole -- an American model and former Miss California USA -- for helping him through his recent ordeal, and says that speaking to a therapist offered stability during his darkest days.
"I didn't want to see a therapist in the beginning but once I did I found that I felt better and I was healthier, I was learning so much more about myself that I didn't know," he says.
"[My wife] is my everything and my rock and helps me through everyday life. I definitely wouldn't be who I am without her. She was somebody who really helped me through my most recent time.
"I do like who I am and I'm comfortable with who I am. I couldn't say that a few years ago. So I'm in a very good place and just living life one day at a time."
Now a paid spokesman for the online therapy company TalkSpace, Phelps is working to try and raise awareness of depression and other mental health issues by telling others about his own journey.
"I'd like to make a difference," he says. "I'd like to be able to save a life if I can. You know for me that's more important than winning a gold medal.
"The stuff that I'm doing now is very exciting. It's hard, it's challenging but it's fun for me. That's what drives me to get out of bed every morning."
Now a father of two boys, Phelps says this time his retirement from swimming is for good. He hopes to travel to Tokyo for the 2020 Olympics, but has no intention to compete.
A Games without the sight of a long-limbed Phelps launching into the pool will be sorely lacking, but the greatest Olympian of all time has no regrets about ending his career at Rio.
"I finished my career on a high," he says. "You know it's how I wanted to do it and I always said to myself I can hang my suit up how I want, it's the best way to retire.
"That chapter is done and the next chapter I hope to be bigger, more exciting and more impactful."
His greatest battle, in many respects, has always been outside the pool.