New research suggests that some teenagers could become depressed and anxious as a result of internet addiction.
The study, carried out in China, involved more than 1,000 teenagers with an average age of 15.
It was designed to investigate the links between mental health problems and excessive internet use.
And scientists urged for more screening to take place at schools in order to identify at-risk individuals at an earlier stage, so they could benefit from treatment and counselling.
As part of the survey, the participants were asked a number of questions designed to spot signs of anxiety or depression.
They included the question: “How often do you feel depressed, moody or nervous when you are off-line, which goes away once you are back online?”
At the beginning of the study, 62 teenagers - 6.2% of the total - were classified as engaging in “moderately” unhealthy internet use, and 2% were “severely at risk”.
Nine months later, the teenagers were re-assessed for anxiety and depression. The findings, reported in the journal Archives of Pediatrics & Adolescent Medicine, showed that 8.4% had developed clinical depression and 0.2% were suffering significant anxiety symptoms.
The authors, led by Dr Lawrence Lam from the School of Medicine in Sydney, Australia, wrote: “This result suggests that young people who are initially free of mental health problems but use the internet pathologically could develop depression as a consequence.”
They added: “Screening for at-risk individuals in the school setting should be considered an effective early prevention strategy.”