London: How much time does your child spend on Facebook? Teenagers who regularly use social networking sites are much more likely to drink, smoke and use marijuana, a new study has claimed.
   
The Columbia University study of 1,000 American teenagers aged between 12 and 17 years found that those who used such sites daily were five times more likely to smoke tobacco than those who did not.
   
Similarly, they are three times more likely to drink alcohol and twice as likely to use marijuana.
   
The poll also found that 70 per cent of those interviewed said they used social networking sites on a typical day, while 30 per cent did not, a newspaper reported.
   
One of the main reasons for going on such sits, besides actually communicating with friends, is to keep tabs on peers by looking at their photographs.
   
But the study found that pictures of teenagers "drunk, passed out, or using drugs on Facebook and other sites" were "rampant".
   
However, parents seemed unaware that browsing such sites could increase their child's likelihood of abusing drink or drugs, with almost nine in 10 believing it did not have an effect on them, the researchers said.
   
Joseph Califano, founder of National Center on Addiction and Substance Abuse at the university, called on operators of Facebook and others to instigate tighter controls to block such photographs.
   
"The time has come for those who operate and profit from social networking sites like Facebook to deploy their expertise to curb such images and to deny use of their sites to children and teens who post pictures of themselves and their friends drunk, passed out or using drugs," he said.
   
The survey also found that one in five teenagers claimed to have been bullied online.

(Agencies)