Fewer than one in 15 young people with a mental health disorder have received a diagnosis from NHS mental health services, according to a new study.
Experts said that most young people with a mental health disorder “don’t receive a diagnosis from these services, even when they’ve had some healthcare contact for these problems”.
So-called “diagnosis gaps” were largest for young people with anxiety and multiple issues, researchers found.
It comes after a major new review found that common mental health problems and mental distress have “increased substantially”, particularly among young women.
The review, published last week by Professor Peter Fonagy, concluded that a rise in mental health problems “is real, is affecting everyday functioning and cannot be explained by greater awareness alone”.
Professor Peter Fonagy
UCL
In 1993, around one in six children and young people met the criteria for a common mental health disorder – and this rose to one in four by 2024, the review adds.
According to data from NHS England, 65,120 people in the capital had an open referral for ADHD In June 2025 - but that figure had soared 72% to 112,570 in June 2026.
Over 27,000 of those on the list have been waiting for their assessment for more than two years.
The new study, published by experts at the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London, examined data on young people in south London.
But researchers said that the figures reported are likely to “reflect or underestimate practices nationwide”.
Experts from the IoPPN examined information from interviews with 2,000 17-year-olds, which indicated whether or not they could be diagnosed with five mental health disorders including anxiety, depression and PTSD, along with population and NHS data.
They found that between 2009 and 2024, diagnosis rates for mental health conditions among 17-year-olds in south London rose from 2.6% in 2009 to 4.4% in 2024.
But fewer than one in every 15 of those estimated to have a disorder actually had a diagnosis, according to the study which has been published in The Lancet Regional Health – Europe.
And among those who had actually reached out for help, fewer than one in four received a diagnosis.
The authors said that the estimated “diagnosis gaps were largest for those with generalised anxiety disorder and multiple disorders”.
“It’s encouraging that more young people are receiving diagnoses from NHS mental health services than in the past,” said lead author Dr Stephanie Lewis, from the IoPPN at King’s College London.
“But our findings suggest that most young people in the population who meet criteria for a mental health disorder don’t receive a diagnosis from these services, even when they’ve had some healthcare contact for these problems.
“This research highlights the importance of strengthening young people’s mental healthcare, so that more young people with disorders can access services that recognise their needs and provide effective, tailored treatment.”
Professor Andrea Danese, senior author of the study from the IoPPN at King’s College London, added: “Diagnosis matters because NHS treatments are disorder-specific, and without it, young people cannot be matched to the care most likely to work.
“Our findings show that most young people with a disorder are not receiving one, including many who have sought help.”
An NHS England spokesperson said: “The results of this small-scale South London study found the proportion of mental health diagnoses of 17-year-olds is increasing with our own figures showing a record number of children in contact with NHS services.
“As Professor Fonagy’s recent review found there has been a genuine increase in the number of young people seeking help in recent years, with calls for young people to receive help before a diagnosis which is why we have ensured six million pupils in England now have easy access to NHS mental health support in their classrooms so they can receive help before and after diagnosis.”