Demi Lovato -- Miley And I Have NOTHING in Common

Demi Lovato and Miley Cyrus -- both Disney disciples and current pop icons -- have cut ties ... so says Demi.

During a radio interview with AMP in Boston, Demi stumbled when asked about her relationship with Miley, but ultimately said the two of them have NOTHING in common.

It's a big statement. The 2 have been friends since they were young, but have been rumored to be on the outs for a while ... especially after Demi became sober. Now Demi has made it pretty clear.

Cue the wrecking ball.