Is Joaquin Phoenix Mad?

Joaquin Phoenix shocked viewers of David Lettermans chatshow during a bizarre appearance earlier this week.

The star of Gladiator and Walk The Line has been increasingly weird in recent months proclaiming that he was quitting acting in favour of a rap career.

Now fans are speculating whether dishevelled Joaquin has actually lost the plot or if hes hoaxing us all.

Appearing on Letterman with a massive beard he gave short answers and seemed to slur.

When asked why he had decided to quit films for music he replied I dont know.

Letterman also asked the star if there were any particular incidents on the set of his new film Two Lovers- which also stars Gwyneth Paltrow.

Phoenix replied Im sure something fun happened, before refusing to introduce a clip of the movie saying he had not seen it!

Well keep you updated on the world of Joaquin. MTV cant wait to hear his rap album!