A landmark 32-year study from Scotland has uncovered a striking pattern that is prompting fresh questions about how childhood mental health treatment is monitored over a lifetime. Researchers found that just 8% of children who attended Child and Adolescent Mental Health Services (CAMHS) later accounted for 46% of adult psychiatric inpatient bed days and 41% of all NHS adult mental health outpatient appointments by their early 30s.

The population-based study, led by the University of Edinburgh, tracked almost half a million people born in Scotland between 1991 and 1998 until 2023. This study represents the UK's longest follow-up of children who received specialist mental health care, highlighting the long-term burden borne by a relatively small group of young patients.

CAMHS are specialist NHS services for children and teenagers experiencing serious mental health problems. Treatment may include medicines, counselling and other psychological therapies. While these approaches often improve symptoms in the short term, researchers say there is surprisingly little evidence on how patients fare decades later.

The study found that four in ten children who attended CAMHS later required specialist adult psychiatric care. Among those first seen during their teenage years, the figure rose to one in two. Former CAMHS patients made up almost half of the adult hospital cases for eating disorders and personality disorders. They also accounted for 39% of schizophrenia cases and 39% of opioid use disorder cases.

Professor Ian Kelleher, Chair of Child and Adolescent Psychiatry at the University of Edinburgh, said: "We know about long-term outcomes for 27 types of cancer in Scotland, but we've known very little about long-term outcomes for children who attend our CAMHS services because there is no equivalent monitoring system for mental health. This is more important now than ever, given the rising number of children and young people presenting with mental health problems."

He added, "CAMHS is not just a childhood treatment service – it identifies a population that will go on to be high-intensity users of specialist adult mental health services. From a health, societal and economic perspective, we need to robustly evaluate whether existing CAMHS interventions are leading to long-term benefits."

The findings do not suggest that childhood mental health treatment is ineffective. Previous research published in journals including The Lancet Psychiatry and JAMA Psychiatry has shown that early intervention can reduce symptoms, improve daily functioning and lower the risk of mental health crises. Instead, the Scottish study highlights a major gap in long-term monitoring, making it difficult to know which treatments provide lasting benefits and which patients may need stronger support as they move into adult care.

To address that gap, the researchers have called on the Scottish Government to establish a Mental Health Observatory that would routinely link childhood and adult mental health records. They argue that such a system could help doctors, researchers and policymakers evaluate the long-term impact of medicines, psychological therapies and service changes, much as cancer outcomes are tracked over many years.

Dr Jane Morris, Chair of the Royal College of Psychiatrists in Scotland, said the findings reinforce the need for early diagnosis while also strengthening adult mental health services to sustain gains made during childhood. She said the college supports creating a mental health observatory to improve lifelong mental healthcare.

The researchers note that the study identifies long-term associations rather than proving that childhood treatments caused later outcomes. They say further research is needed to determine which interventions are most effective in changing the lifelong course of serious mental illness.