LOS ANGELES (AP) — Athletes Stephen Scherer, Jeret Peterson and Kelly Catlin have two things in common: They all reached their dream of becoming Olympians, and they all died by suicide.

Olympians are known for pushing their bodies to the extreme but much less understood are the mental and emotional rigors paving their road to greatness. Michael Phelps, the most decorated Olympian in history, says he had suicidal thoughts even at the peak of his remarkable swimming career, and calls depression and suicide among Olympic athletes an “epidemic.”

Phelps is opening up about his mental health struggles in “The Weight of Gold,” a new documentary that premiered last week on HBO. The film explores depression and suicide among the world’s top athletes and what should be done to address the problem.

Other high-profile Olympians including speed skater Apolo Anton Ohno, snowboarder Shaun White, skier Bode Miller, hurdler Lolo Jones and figure skater Sasha Cohen also detail their own struggles in the film.