A research by Public Health England (PHE) has revealed that children who spend too much time on internet face the risk of mental and social problems such as loneliness, depression, anxiety, low self-esteem and heightened aggression.
The survey said that though less usage can also lead to the problems, the relationship was more evident when children are found online for over four hours a day.
According to Daily Mail, one in 10 children have mental health problems and one third of teenagers feel "low, sad or down" at least once a week.
The report said, "Children who spend more time on computers, watching TV and playing video games tend to experience higher levels of emotional distress, anxiety and depression. The evidence suggests a 'dose-response' relationship, where each additional hour of viewing increases children's likelihood of experiencing socio-economic problems, and the risk of lower self-esteem."
The prime time when mental issues start is eight to 15 years. Fifty per cent of lifetime mental ill health starts at age 14 and 10 per cent children today have some kind of mental issue.
As per PHE figures, from 2006 to 2010, the percentage of youngsters playing computer games for two hours or more a night during the week went up from 42 per cent to 55 per cent among boys and 14 per cent to 20 per cent among girls.
The report also said that the number of calls to ChildLine related to online bullying, suicidal thoughts and self-harm has soared in recent years.