Fewer than one in 15 South London teenagers with likely mental health disorders diagnosed by NHS

A King’s College London study found that most 17-year-olds likely to have a mental health disorder were not diagnosed by NHS services, with girls and ethnic minority young people facing a wider gap.

A new King’s College London study suggests that fewer than one in 15 young people in South London who are likely to have a mental health disorder received a diagnosis from NHS mental health services, raising fresh concerns about how many children and teenagers are being missed by the system. The research, from the Institute of Psychiatry, Psychology & Neuroscience, examined diagnosis rates among 17-year-olds between 2009 and 2024 by comparing electronic health records with population estimates and epidemiological data. According to King’s College London, the findings were published in The Lancet Regional Health – Europe.

The study found that the share of 17-year-olds in South London diagnosed with any mental health disorder by NHS services increased from 2.6% in 2009 to 4.4% in 2024. Even so, the researchers concluded that most young people in the wider population who met criteria for a disorder did not receive a diagnosis, including many who had already sought help from a health professional. The team based its estimates on interviews with more than 2,000 young people in the nationally representative Environmental Risk Longitudinal Twin Study, which it weighted to reflect the characteristics of 17-year-olds in South London.

The gap was not uniform across groups. The researchers said girls were less likely than boys to receive a diagnosis when they were estimated to have a disorder and had already seen a health professional. Young people from Black, Asian, mixed or other ethnic backgrounds were also less likely than White young people to receive a diagnosis. The study suggested that part of the shortfall was linked to barriers before young people ever reached specialist care, including uncertainty about when to seek help, worries about confidentiality and practical problems getting to appointments. But the authors said that did not explain everything, because fewer than one in four of those estimated to have a disorder and who had seen a health professional, including GPs and counsellors, were diagnosed by NHS mental health services.

Stephanie Lewis, the study’s lead author at King’s College London, said the rise in diagnoses was encouraging, but added that most young people with disorders were still not receiving one, even when they had already had some contact with healthcare. Andrea Danese, a senior author at the university, said diagnosis matters because NHS treatment is often matched to specific disorders, and argued that the findings strengthen the case for more investment in assessment capacity. The researchers said their figures are likely to reflect, or even overstate, practice across England. They said the results were consistent with the STADIA trial, which found that around one in eight children referred to community mental health services across eight large NHS trusts in England received a recorded diagnosis within a year, even though two-thirds of those assessed screened at high probability of a common mental disorder.