Yahoo! Movies has just debuted the first theatrical trailer from the highly-anticipated documentary I'm Still Here, which will premiere in theaters on September 10. Click on the video player below to catch your first video glimpse at this documentary focusing on Joaquin Phoenix. You can read the full synopsis below the video player as well:

The directorial debut of Oscar-nominated actor Casey Affleck, I'm Still Here is a striking portrayal of a tumultuous year in the life of internationally acclaimed actor Joaquin Phoenix. With remarkable access, I'm Still Here follows the Oscar-nominee as he announces his retirement from a successful film career in the fall of 2008 and sets off to reinvent himself as a hip hop musician. Sometimes funny, sometimes shocking, and always riveting, the film is a portrait of an artist at a crossroads. Defying expectations, it deftly explores notions of courage and creative reinvention, as well as the ramifications of a life spent in the public eye.