Justin Bieber is here for the long-term and is just growing up in the public eye, Usher has said.
The RnB star was speaking at the world premiere in Los Angeles of Justin's new documentary film Justin Bieber's Believe.
"I mean more money, more problems," Usher said.
"The beautiful part about it is that those that are invested in a long term story, you understand that there are peaks and valleys in every person's life.
"Unfortunately the reality is he has to live with a camera in front of him, but what he chooses to do on or off camera is analysed or scrutinised in some off way."
Controversy surrounded the star this year on everything from turning up late to his gigs in London to having to apologise to Bill Clinton for cursing the former US president and spraying his photo with cleaning fluid in a New York City restaurant kitchen.
His long-time manager Scooter Braun agreed that Justin had a crazy 2013, adding: "Pandora's box was opened. I mean he got a little bit into trouble."
"It's tough because the whole world is a critic," said Justin's mother Pattie Mallette. "I think sometimes people dehumanise celebrities and I think what's so great about this movie is that you get to see his humanity."
Justin's grandmother Diane Dale rallied to the teenage star's defence, saying: "I think the media has been terrible on him. There are so many lies going around. A little bit is true but most of it is lies. It's terrible."
Justin Bieber's Believe, which opens in US cinemas on Christmas Day, captures a behind-the-scenes look at the 19-year-old star.