Experts are highlighting the "worryingly high" rates of mental-ill health in young people after a new study revealed the prevalence of depression amongst teenage girls.

Researchers from the UCL Institute of Education and the University of Liverpool looked at data from over 10,000 children born in 2000-01 who are taking part in the Millennium Cohort Study. They found that nearly a quarter of 14-year-old girls and one in 10 boys of the same age are depressed.

In total, 24% of 14-year-old girls reported high levels of depressive symptoms.

The researchers also questioned parents about their children's mental health when their youngsters were aged three, five, seven, 11 and 14. When the participants were 14, the children were themselves asked questions about mental health difficulties.

The research showed that girls and boys had similar levels of mental ill-health throughout childhood until adolescence, with 7% suffering such problems aged seven, rising to 12% by the age of 12.

But stark differences were seen between gender by adolescence, when problems became more prevalent in girls. The studies data has prompted fresh questions about how social media, body image issues and school-related stresses affect young people’s mental welfare.

The research also strongly suggests that being from a low-income family increases the risk of depression and that ethnicity is potentially a key factor too.

Lead investigator Dr Praveetha Patalay, from Liverpool University, said teenagers, and particularly girls, were facing more mental health difficulties than previous generations - although the study did not look at this.

Anna Feuchtwang, chief executive of the National Children's Bureau, comments: "This study of thousands of children gives us the most compelling evidence available about the extent of mental ill-health among children in the UK. With a quarter of 14-year-old girls showing signs of depression, it’s now beyond doubt that this problem is reaching crisis point.

"Worryingly there is evidence that parents may be underestimating their daughters' mental health needs. Conversely, parents may be picking up on symptoms in their sons, which boys don’t report themselves. It's vital that both children and their parents can make their voices heard to maximise the chances of early identification and access to specialist support.

"The new research also suggests that signs of depression are generally more common among children from poorer families. We know that mental health doesn’t exist in a vacuum and as the government prepares to publish its plans to improve children’s wellbeing, it must address the overlap with other aspects of disadvantage."