KEY POINTS:
Children who watch television more than two hours a day are more likely to have attention problems when they are teenagers, according to Otago University researchers.
The new study is the first to investigate a possible long-term link between television viewing in childhood and attention problems in adolescence.
The roughly 40 per cent increase in attention problems among heavy TV viewers was observed in both boys and girls, independent of whether a diagnosis of attention deficit/hyperactivity disorder was made prior to adolescence.
The study followed more than 1000 children born in Dunedin in 1972-1973. The time they spent watching television was recorded every two years between the ages of five and 11.
Researcher and paper co-author Erik Landhuis said today that those who watched the most television had more difficulty paying attention when they were teenagers.
The attention problems were reported by their parents, teachers and the participants themselves.
Young children who watched a lot of television were more likely to continue the habit as they got older, but even if they did not the damage was done, the report said.
"This suggests that the effects of childhood viewing on attention may be long lasting," Mr Landhuis wrote.
Co-author Bob Hancox said the findings suggested that childhood television viewing might contribute to the development of attention problems.
Those who watched more than two hours - and particularly those who watched more than three hours - of television per day during childhood had above-average symptoms of attention problems in adolescence.
Symptoms included short attention span, poor concentration and being easily distracted.
These findings could not be explained by early-life attention difficulties, socioeconomic factors or intelligence.
Even after all of these factors were taken into account, watching more television was associated with teenage attention problems, Dr Hancox said.
"Although teachers and parents have been concerned that television may be shortening the attention span of children, this is the first time that watching television has been linked to attention problems in adolescence.
"This latest study adds to the growing body of evidence that suggests parents should take steps to limit the amount of TV their children watch."
Previous studies by Otago University had linked children's excessive TV viewing to childhood obesity, a range of health problems in young adulthood, as well as lower educational achievement.
"These findings support the recommendation of the American Academy of Paediatrics to limit children's television to a maximum of two hours per day," Dr Hancox said.
The research comes out of the University's long-running Dunedin Multidisciplinary Health and Development Study and appears in the latest issue of the US journal Paediatrics.
- NZPA