Siegfried & Roy are two of the highest paid entertainers in the world, but life hasn't always been easy for the popular magicians.

"Our audience is giving us what we missed in our childhood ? love," says Roy Uwe Ludwig Horn on this Sunday's E! True Hollywood Story (9 pm/ET). The documentary traces the difficult childhoods of Horn and Siegfried Fischbacher, German-born magicians who both grew up in abusive households under the Nazi regime.

"You grow up hearing, 'You cannot do this, you cannot do that. You're going to be no good,' " says Siegfried. "And you hear that all your life growing up, you believe into that. Now when you grow up and all of a sudden people say, 'You can do that,' that can be a very frightening experience. And that's the stress. You don't sleep. You get ulcers. The demons don't stop for me.' "

Siegfried confesses that he eventually developed a drug addiction as a way of coping with the pain. The addiction became so severe, in fact, that he was even hallucinating onstage while he was supposed to be focusing on taming the lions and tigers in the act.

"We recognized that there was a problem and we tried to solve it," says Roy. "So he went to Puerto Rico and took all the valiums, threw them away. He cured himself. He has tremendous willpower."