Smartphone use has been linked to soaring teenage obesity and depression rates, sparking fresh concerns over when children should be introduced to the devices.
A new study of more than 1,950 adolescents found that owning a smartphone by age14 was associated with higher risks of depression, obesity, and poor sleep.
Teenagers who had a phone by this age and spent around five hours a day on it were more than twice as likely to suffer from depression and obesity.
Researchers said a lack of sleep is driving the trend, with excessive screen time posing a growing threat to children's mental and physical health.
They concluded that keeping phones out of the bedroom at night and limiting screen time could help mitigate the risks.
