simone biles,
Gold medalist Simone Biles celebrates at the medal ceremony for the Women's Floor at the Rio 2016 Olympic Games. (Photo by Alex Livesey/Getty Images)

On Tuesday, Simone Biles opened up about her struggles with ADHD after Russian hackers made the medical records of several U.S. Olympians, including Biles, available online.

Biles had tested positive for methylphenidate, also often known as Ritalin, the World Anti-Doping Association (WADA) disclosed. Methylphenidate is a banned substance, but Biles had received an exemption because of her medical condition.

“Simone has filed the proper paperwork per USADA and WADA requirements, and there is no violation,” Steve Penny, president of USA Gymnastics, said in a statement. “The International Gymnastics Federation, the United States Olympic Committee and USADA have confirmed this. Simone and everyone at USA Gymnastics believe in the importance of a level playing field for all athletes.”

Biles took the opportunity not just to share her support for clean Olympic Games but also to open up about her struggles with ADHD.

She took to Twitter to say, “I have ADHD and I have taken medicine for it since I was a kid. Please know, I believe in clean sport, have always followed the rules, and will continue to do so as air play is critical to sport and is very important to me.”

“Having ADHD, and taking medicine for it is nothing to be ashamed of nothing that I’m afraid to let people know,” she tweeted out.

Serena Williams and Venus Williams were also among the list of athletes whose medical records were compromised in the Russian hack.