More teenagers are becoming addicted to the internet with an estimated 930,000 junior high and high school students nationwide overusing online services, a health ministry team said Friday.

The figure is double the number from the previous survey in 2013, and showed that more female students were hooked than males. The team said the prevalence of smartphone games and social networking services is partly to blame for the surge.

Internet addicts can become reclusive or violent toward family members and might be at risk of neurological problems and illnesses such as depression.