Children that spend more than two hours a day at a PC or watching TV could suffer from mental health problems.

Research by the University of Bristol, which has been published by Pediatrics revealed that while sitting in front of a screen doesn't cause mental health problems, kids that were exposed to screens for prolonged periods of time were more likely to develop difficulties dealing with emotion, interaction or even hyperactivity problems.

"Whilst low levels of screen viewing may not be problematic, we cannot rely on physical activity to 'compensate' for long hours of screen viewing," said Angie Page, who led the study.

"Watching TV or playing computer games for more than two hours a day is related to greater psychological difficulties irrespective of how active children are."

The study also revealed that the likelihood of developing mental illness was not affected by the amount of physical activity the child participates in.

See also: Children under 9 years old 'shouldn't use a PC'