The first feature in this programme looks at the research being done to monitor the brains of teenagers with internet addiction:
https://www.bbc.co.uk/programmes/w3ct5t8n
These studies show that the brains of teenagers are different to teenagers who have a healthy use of the internet.
This programme looks at a group of 5 teenagers who agreed to give up their smartphones for five schooldays. There were some surprising results:
https://www.bbc.co.uk/programmes/m00209dl