MARIAH CAREY - MARIAH'S REST RULES

MARIAH CAREY insists on sleep and vocal rest in a bid to make sure she doesn't suffer a breakdown like the one that halted her career and put her in hospital in 2001.

The pop superstar takes much better care of herself these days and always sets aside days of total silence.

She tells men's magazine BLENDER, "It's a question of getting myself solidly balanced. But I'm much better at sleeping because I have to be."

And on the days when she decides she isn't going to speak, she texts her pals "I'm having a vocal rest" on her cellphone to alert them not to call her.