I found this from 2016:
Simone Biles on Her ADHD: 'It's Nothing That I'm Afraid to Let People Know'
Simone Biles’s privacy was seriously invaded this week, when Russian hackers attacked the World Anti-Doping Agency's athlete database and released medical information about the USA gymnast.Biles has apparently had a "therapeutic use exemption" from the relevant oversight agencies to use the drug and still compete.According to ABC News, the published documents revealed that Biles had received a medical exemption to take methylphenidate, a stimulant used to treat ADHD that's typically banned. Ever the role model, 19-year-old Biles took to social media yesterday to clear up any confusion about her medication: "I have ADHD and I have taken medicine for it since I was a kid," she tweeted. "Please know, I believe in clean sport, have always followed the rules, and will continue to do so as fair play is critical to sport and is very important to me."
If the hackers were hoping to smear Biles’s image, they failed. As ABC News senior medical correspondent Jen Ashton, MD, explained, drugs like methylphenidate (known by the brand name Ritalin) "are thought to work by enhancing neurotransmitter function in the brain." They would not affect an athlete's performance, she said.
Biles wasn't the only target of the hackers: They also published medical information about Serena and Venus Williams.
-PJ
So does this mean she is allowed to take it in Japan