Can someone please tell me why fame has the ability to seemingly strip a human being of dignity or self-respect?

This question has been on my mind for quite a few months. During my news reading I am often bombarded by someone's attempt to secure fame. Whether it's a celebrity showing an uncomfortable amount of flesh, acting like an ass, or allowing people to violate them, it all seems to be an attempt to either keep or create their fame.

Is fame like a drug? Not all celebrities are under it's influence, but the ones that are ... seem willing to do Anything to get their fix.