It's been two weeks since Prince was found dead, but exactly what killed him remains a mystery.A former attorney for Prince's siblings, who are now deceased, says the siblings revealed to him that Prince had an addiction to Percocet decades before his sudden death. However, Dr. Drew is hesitant to say "addiction," and talks with Ryan Donnelly, a recovering opiate addict and the founder of Free From Hell, about the difference between opioid addiction and opioid dependency.