Online addiction is having more serious harm on teens that underage sex or alcohol addictions. 
That's according to author and social researcher David Gillespie in this new book Teen Brain, which focuses on why screens are making your teenager depressed, anxious and prone to lifelong addictions.
Much of the focus and attention around screen time has centred around young children with the World Health Organisation issuing the first ever guidelines for children age four and under.
Now Gillespie’s book, with the focus on the unique aspects of the teenage brain, is giving us reason to question how much time our adolescent children should be spending on devices and in front screens.
Gillespie told Francesca Rudkin that online addictions have been climbing over the last decade, surpassing previous addictions such as binge drinking and cigarette smoking. 
Yet while those addictions have dropped, the side effects of them - such as depression and anxiety - are changing in the opposite direction. 
"Not only is it not dropping or staying the same, it's doubling. The addictions that require you to be physically present have dropped, but the consequences have not, because what we've done is addict all of the kids with software." 
Gillespie says that software has targeted boys and girls through "danger porn" and "approval porn", using video games and social media likes to get them hooked. 
He says that changes in parenting habits, such as parents working more and having fewer children, have made it easier for tech companies to go after children. 
"Tech companies realised that parents were gatekeepers to their primary audience. And now they have re-engineered and today have things like Fortnite, which have turned it all into a cartoon."