Scientists have identified an ‘invisible risk' group among teenagers, who appear to have a higher prevalence of psychiatric symptoms, such as depression and suicidal thoughts.

According to their study, which involved over 12,000 young people aged 14 to 16 in 11 European countries, teenagers who use the media a lot, who have low physical activity levels and who do not get enough sleep make up this ‘invisible risk' group.

When it came to risk behaviours and psychiatric symptoms, an analysis of the results revealed three risk groups - high, low and invisible.

Some 13% of teenagers were found to be at high risk, while 58% were at low risk.

The scientists from Sweden said that while these two risk groups were expected, the third ‘invisible' group was not. These young people displayed high levels of media use, reduced sleep and sedentary behaviour.

The scientists noted that these behaviours are not usually associated with mental health issues among parents and teachers. However the teenagers in this ‘invisible' group displayed similar levels of anxiety, depression and suicidal thoughts as the teenagers in the high risk group.

"While the 'high' risk group is easily identified by behaviour such as alcohol and drug use, parents and teachers are probably not aware that adolescents in the 'invisible' risk group are at risk," the team from the Karolinska Institutet said.

The study also found that while risk behaviours tended to be more common among boys, emotional psychiatric symptoms, such as anxiety and depression, were more common among girls.

Details of these findings are published in the journal, World Psychiatry.

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