Yahoo SportsDenny Hamlin: Comment that '70 percent' of drivers use Adderall was a jokeYahoo SportsDenny Hamlin speaks during media day for the NASCAR Daytona 500 auto race at Daytona International Speedway, Wednesday, Feb. 14, 2018, in Daytona Beach, Fla. (AP Photo/Terry Renna). More. Denny Hamlin says he was joking when he quipped that 70 percent ...and more »