Pop star/actress Hilary Duff struggles with sleep deprivation - because she can't go to bed until her living space is spotless.

The So Yesterday singer also admits she cannot sleep past 7am, and even cleans up hotel rooms before checking out - because she can't abide mess of any kind.

She tells Maxim magazine, "I'm Ocd (obsessive compulsive disorder) when it comes to cleaning. I can't go to bed with a messy room. That would totally wig me out. It freaks me out to have dishes in the sink."

"I practically clean my hotel room before I check out. I wish I weren't psychotic like that, but I am."

And Duff's early rising addiction disturbs her pals.

She adds, "No matter how late I stay out the night before, I will wake up at 7am. It's kind of sick."

"My friends are like, 'What are you doing up? Go to bed. That's creepy.'"