LOS ANGELESJustin Bieber had several blocks of downtown L.A. teeming with screaming fans trying to catch a glimpse of him for the premiere of his movie, "Never Say Never," on Tuesday night (February 8).

Given the mass hysteria caused by the 16-year-old star — a condition commonly referred to as Bieber Fever, which includes a variety of "symptoms" ranging from frequent high-pitched shrieks, an affinity for the color purple, etc. -- we asked a few of the stars in attendance to explain to MTV News what Bieber Fever means to them.

"Bieber Fever is everything," admitted Bieber fan and fellow musician Asher Roth. "It's everything." Roth was so full of the Fever that he came to the event with props: two sparklers in the shape of a "J" and "B." "It's for real," the "I Love College" rapper said of his fandom. "The fire marshal wouldn't let me light them, though."

"Bieber Fever is a set of symptoms that are almost indescribable and uncontrollable," Disney star Debby Ryan explained. "There is sweeping your hair out of your face, even if it's not in your face. There's singing and dancing randomly to songs that aren't being played out loud, things like that. I'm a doctor," she jokingly added.

"I think that the only medication for Bieber [Fever] is to Bieber more," the "Suite Life on Deck" actress continued. "There's a [Henry David] Thoreau quote: 'The only remedy for love is to love more,' and I think that it's the exact same thing. The only remedy for Bieber [Fever] is to Bieb more."

According to the man himself, it's all about his fans and the love he has for them.

"Bieber Fever is, I don't know," Bieber said. "I think it's my fans being really supportive. They made it up. At the end of the day, my fans are my everything, and they got me to this position."

"Keeping Up With the Kardashians" younger siblings Kylie and Kendall Jenner said Bieber Fever is a special kind of malady.

"It's a very exciting sickness. It's something that a lot of girls want. It's a great excuse to stay home from school," Kylie said. "There's no cure. It's not dangerous at all."

"It benefits you," Kendall added.

What do you think Bieber Fever is? Tell us in the comments!

Check out everything we've got on "Justin Bieber: Never Say Never."

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