Damage to psychological functioning merits serious concern, finds poll.

Almost one in 10 US video gamers aged 8 to 18 can be classified as " clinically addicted" to video games, new research has warned.

An online study conducted by Harris Interactive in January found that 23 percent of young gamers have felt " addicted to video games". About one-third of males and a little more than one in 10 females report feeling "addicted".

The survey of 1,178 US children and teenagers also found that 44 percent believe that their friends are addicted to games.

It estimates that nearly eight in 10 young Americans play video games at least once a month, including 94 percent of all boys.

Video game playing time was found to differ by age as well as gender. The average eight to 12 year-old now plays 13 hours of video games per week, while the average 13 to 18 year-old plays for 14 hours.

Dr Douglas Gentile, director of the Media Research Lab at Iowa State University, and director of research for the National Institute on Media and the Family, said: "It is important that people realise that playing a lot is not the same thing as pathological play.

"For something to be an addiction, it has to mean more than 'you do it a lot'. It has to mean that you do it in such a way that it damages your life. This is why we based our definition on how pathological gaming is diagnosed in the DS M-IV. 

"Almost one in 10 youth gamers show enough symptoms of damage to their school, family and psychological functioning to merit serious concern."

Dr Suzanne Martin, youth and education researcher at Harris Interactive, added: "The prevalence of video gaming in youth culture, in combination with this level of pathological video gaming, is great cause for concern and highlights the need for further research in this area."

Gamers who were surveyed and classified as pathological were receiving lower grades in schools than their peers, and were more likely to have video game systems in their bedrooms.

They were also spending much more time playing games each week (average 24.5 hours), and were more likely to have been diagnosed with an attention deficit problem.