Analysis from the National Lottery-backed mental health programme HeadStart found that emotional difficulties for girls increased by 17 per cent between the ages of 11 and 14.
In contrast, boys of the same age are one of the most stable groups of young people in terms of mental wellbeing, with emotional problems decreasing slightly, by five per cent, in their early teens, researchers found.
Mental health experts say the findings show the need to invest in supporting pre-teen and younger adolescents with their mental health as they make the move from primary to secondary school.
The study involved the views of more than 10,000 children aged 11 to 14, carried out by the programme’s evidence gathering unit based at children’s charity Anna Feud Centre and University College London.
“This new evidence from HeadStart is a wake-up call to us all not to wait until young people show clear signs of mental distress as older teenagers – but to act early,” said Professor Jessica Deighton, director of innovation, evaluation and dissemination at the Anna Freud Centre.
“This escalation is happening at a time of enormous physical, emotional and social change for young people, and can be heightened during a child’s transition from primary to secondary school.
“Such challenges can pose a threat to young people’s mental health, and if not tackled, may continue into adulthood.
“These findings show a worrying trend in relation to girls as they progress through adolescence, but they also highlight the start of secondary school as a period of opportunity to support pupils with their emotional wellbeing. Schools and families need to be ready to intervene positively to prevent problems from escalating.”
HeadStart, which is backed by £58.7m in National Lottery funding, already runs projects to support children's mental health when they make the transition from primary to secondary school.
This includes the Moving On Up project in Blackpool, which helps 10- to 11-year-olds and covers issues such as friendship, problem solving and confidence building. Another project in Hull involves recruiting and training young people to mentor children moving up to secondary school.
A survey of school leaders released earlier this week found that the proportion of schools in England employing mental health counsellors has nearly doubled since 2016, from 36 per cent that year to 66 per cent last year.
Boosting mental health support in schools has been a cornerstone of the government’s recent health policy, as laid out in 2017’s Transforming Children and Young People’s Mental Health Provision: A Green Paper.
But the children’s commissioner for England, Anne Longfield, has warned that the NHS is still a decade away from being able to offer children and young people a “decent” mental health service.