Tokyo (AFP): Four-time Olympic diving gold medallist Shi Tingmao has revealed her struggles with depression, joining US gymnastics superstar Simone Biles in openly discussing her mental health at the Tokyo Games.

China's Shi comfortably won the 3m springboard title for her second gold in Japan but cut a tearful figure in the immediate aftermath at the Tokyo Aquatics Centre.

The 29-year-old later said she had considered quitting diving after her form dipped last year.

"I have to really take care of my mental state and make sure I don't get into a depression," Shi told a post-competition press conference in unusually open comments for China's often-guarded athletes.

"I have worked with a psychiatrist or psychologist who helped me quite a bit with some of the mental stresses of being a competitive diver and dealing with depression and things like that."

Hinting that she reached such a low that she might have given up the sport, she added: "I really love diving and I realised that there was no way that I could give it up.

"So to get to this point today was not easy."

Shi, who also won two golds at Rio 2016, revealed the internal conflict she has had to deal with.

"There are two of me in my mental state that actually fight with one another," she said.

"Part of me says 'you're a gold medallist, you can take a break, you can be done'. Another part of me says 'you can't give this up, you love diving'."

Shi said she had not seen her family for 18 months because she had been so dedicated to her training and "we actually had very little contact".

"I'm sure my family have been worried for me but I also hope, through the screen, when we see each other, I can speak to my family and say that they have nothing to worry about, everything's fine."

Gymnast Biles came to the Tokyo Games as one of the standout stars but she has pulled out of a series of events and admitted she needed to take care of her mental wellbeing.

It comes weeks after another of the world's highest-profile athletes, Japanese star Naomi Osaka, took a break from tennis after revealing she had suffered depression.