More than 135,000 children and young people in Wales are estimated to have a diagnosable mental health condition, according to Public Health Wales.

The ‘Health Needs Assessment: Mental Health of Babies, Children and Young People in Wales’ report draws on evidence to assess need from early life through to early adulthood. It calls for joined-up action across health, education and wider public services.

The report estimates that one in six children aged eight to 10, one in five aged 11 to 16, and one in four aged 17 to 24 have a diagnosable mental health condition. It also suggests one in four girls and around one in two trans or gender-questioning secondary pupils report low mental wellbeing.

It says the biggest increases are in emotional difficulties such as anxiety, alongside rises in eating disorders and self-harming behaviours across all genders. Children from deprived communities are disproportionately affected, with problems emerging earlier and becoming more severe in adolescence.

The report highlights factors driving poor mental health, including poverty, inequality, academic pressure, parental mental health and digital technology. It also points to protective factors such as relationships, community, physical activity and creativity.

It warns mental health problems were estimated to cost the Welsh economy £4.8 billion a year even before the COVID-19 pandemic.

Early childhood is critical. The report says around a quarter to a third of parent-infant relationships may need support in the first 1,000 days of life, yet most do not receive help before age two. Early intervention brings long-term benefits and is cost-effective.

Emily van de Venter, lead consultant in mental wellbeing at Public Health Wales, said: “There are too many children and young people in Wales who are experiencing distress, low mental wellbeing and mental health conditions. These young people have faced huge challenges including the pandemic, financial insecurity and challenging digital environments.

“Our young people are our future, and they need support as they go through these challenges and it’s important that we listen to their concerns and support them.

“Mental wellbeing needs to be placed at the heart of social, economic and environmental policy and that starts from the very early years of life.”

Simon Jones, head of policy and campaigns at Mind Cymru, said: “We’ve known for some time that children and young people’s mental health services haven’t been keeping up with the level of demand in Wales.

“What Public Health Wales’ findings show us is that the baseline level of need today is such that there must now be a relentless focus on, and investment in, tackling the barriers to accessing support children and young people continue to face, and we look forward to working with a range of partners to help achieve this.”

If you or someone you know is struggling with mental health difficulties, support is available. NHS 111 (press 2) offers 24-hour access to mental health professionals in Wales. The CALL Mental Health Helpline is available on 0800 132 737 or by texting help to 81066.