Tennis Star Naomi Osaka Withdraws From French Open

Naomi Osaka, the world's number 2 ranked women's tennis player, was fined $15,000 for skipping media obligations. She stated on social media that she never intended to be a distraction. Osaka refused interviews due to mental health concerns and revealed she has experienced depression since the 2018 US Open.

What mental health issues did Naomi Osaka mention she has been suffering from?

Since when has Naomi Osaka been experiencing long bouts of depression?