The Norwegian team said ambitious types were less likely to become addicted as they took advantage of the site for their own purposes, such as work and networking.
Rotorua's Stacey Brell said she wouldn't know what to do with her day if she didn't have Facebook.
"I have it logged in on my iPod all day, so I check it throughout the day." Miss Brell said she used the social networking site to keep in touch with friends and family.
"I really enjoy it. You see what people are up to.
"I have been able to connect with some old friends through Facebook," she said.
"I mainly just use it to post status updates and to comment on other people's posts and photos."
She said she would probably qualify as a Facebook addict.
"I don't see that as a bad thing," she said.
"It's funny, when I am at family get togethers some family members tell me that they don't need to come round for a catch up because they see everything I am up to on Facebook."
Miss Brell said it was easy to believe that women were more likely to be addicted to the site.
"Most guys I know aren't even on Facebook."
Another Rotorua woman, who only wanted to be known as Laura, said she was on Facebook constantly throughout the day.
"I check out what all my friends are up to and comment on their status updates and I am always putting posts up about things which I think are interesting."
She said she didn't feel like the amount of time she spent on the site had a negative impact on her life.
"If anything Facebook makes life better and easier," she said.
Laura said she often thought about things she could post on Facebook.
"I think of funny status updates or think about funny photos I could take. It's all in good fun."
Rotorua clinical psychologist Felicity Leach said she hadn't heard of people being addicted to Facebook.
"I have however, talked to people who have been addicted to different computer activities."
Mrs Leach said people could get addicted to anything and most addictions were comfort-based.
"I wouldn't say people were addicted to Facebook, I think a lot of people do spent too much time on the site," she said.
"I think the amount of time you spend on there could have some kind of impact in your life.
"It is the difference between a virtual relationship and a real, physical relationship."
Facebook facts
Founded by Mark Zuckerberg, with college room-mates Eduardo Saverin, Dustin Moskovitz and Chris Hughes, in 2004.
It evolved from a site Zuckerberg had written called Facemash, which compared photographs of students and asked viewers to choose the "hotter person".
Zuckerberg was involved in an acrimonious court case with Harvard students Cameron and Tyler Winklevoss and Divya Narendra over the origins of Facebook. It was settled in 2008 with Facebook transferring 1.2 million shares and paying $20 million in settlement.
Membership was initially limited to Harvard University but has since expanded to include anyone aged 13 and over.
There are now over 900 million active users worldwide.
A 2010 report by Social Media Today estimated 41.6 per cent of the US population had a Facebook account.
The 2010 film, The Social Network, based on Facebook's birth, received eight Academy Award nominations and won Best Motion Picture Drama, Best Director, Best Screenplay, and Best Original Score at the Golden Globe Awards.
Facebook went public recently, floating on the NewYork Stock Exchange or Nasdaq, at an estimated value of US$100 billion.
Are you addicted to Facebook?
An answer of "often" or "very often" to four or more of the below suggests you are:
You spend a lot of time thinking about Facebook or planning use of Facebook
You feel an urge to use Facebook more and more
You use Facebook in order to forget about personal problems
You have tried to cut down on using Facebook without success
You become restless or troubled if you are prohibited from using Facebook
You use Facebook so much that it has had a negative impact on your job/studies
