PARIS—Japan’s Naomi Osaka stunned the French Open on Monday when she announced she was withdrawing from the tournament in the wake of her decision to boycott post-match media duties, explaining she had been suffering from depression for almost three years. Osaka said in the build-up to the tournament that she would not attend the obligatory press conferences, citing that the way journalists quiz players adversely impacts her mental well-being. The four-time Grand Slam champion made good on her threat on Sunday when, after winning her first round match, she did not hold a press conference. She was fined $15,000 by the Roland Garros referee and Grand Slam organizers later issued a statement warning of possible expulsion from the French Open and future majors if she fails to change her stance. On Monday, the world number two decided to take matters into her own hands to end the stand-off. “This isn’t …