More than 30 per cent of students surveyed recently said they were addicted to the internet and felt anxious and irritable when they were stopped from logging on.
The Hong Kong Federation of Youth Groups' social workers interviewed 1,508 secondary students from 31 schools in November and December.
About a third of the respondents - 266 male and 208 female - said that they were addicted to the internet in that year. Other addictions afflicting students included drinking (26 per cent), gambling (12 per cent) and smoking (4 per cent).
Reasons cited for their addictions included 'killing time', 'deriving pleasure from the behaviour', and 'lessening unhappiness'.
Ah Sit, a Form Four student, said he had been addicted to Facebook and online video games for four years.
'My academic performance suffered because of my addiction,' he said. 'I had to repeat Form Four studies this year. The addiction also alienated me from my family. Arguments frequently break out between us when they switch off the computer or unplug the modem to stop me playing games.'