Mobile phones and computers may have overtaken television as the root of all evil for teenagers' poor wellbeing, an Australian study shows.
University of Sydney researchers investigated the impact of technology on more than 1100 Australian teenagers' sleeping habits, finding that those who were unable to switch off from interacting with mobile devices at night were most likely to be sleep deprived.
More than half of those surveyed had two or three devices in their bedrooms, including mobile phones, computers and televisions, but for once, TV was not the problem.
"Television has been the root of all evil for so long that people are used to seeing it associated with unhelpful behaviour," said Dr Nathaniel Marshall from the university's Centre for Integrated Research and Understanding of Sleep.
"We didn't find that."
Instead, it was interactive devices, including mobile phones that teenagers found themselves glued to for hours, or in some cases, all night, to the extent they were suffering from a form of "social jetlag", Dr Marshall told AAP.
But he said researchers could not rule out that other factors were causing sleep problems.
"Maybe these kids have got sleep problems and what they are doing while they can't sleep is using these technology devices," he said.
Simply having the devices in teenagers rooms was not problematic, as some could refrain from using them and enjoy normal sleep patterns, he said.
"The presence of these devices is not the problem, it's when these kids can't help themselves but use it all night," Dr Marshall said.
He said the study was carried out to investigate the extent to which teenagers were sleep deprived because of intense technology use as this could potentially impact their school performance.
Dr Marshall will present the research this week for the first time at the Australasian Sleep Association Conference in Darwin.