Predictors of transitioning to adult mental health services and associated costs : a cross-country comparison

Background: Young people are at risk of falling through the care gap after leaving child and adolescent mental health services (CAMHS) despite an ongoing need for mental health support. Currently, little is known about the predictors of transitioning to adult mental health services (AMHS), and associated healthcare and societal costs as young people cross the transition boundary.


Objective: To conduct a secondary data analysis exploring predictors of transitioning or falling through the gap and associated costs.


Methods: Data were used from a longitudinal study, which followed young people from seven European countries for 2 years after reaching their CAMHS boundary. Predictors of transitioning (including sociodemographic and clinical variables) and longitudinal resource use were compared for 488 young people who transitioned to AMHS versus those who fell through the gap.


Findings: Young people were more likely to transition to AMHS if they were severely ill. Those from Italy, the Netherlands and the UK were more likely to fall through the gap than transition to AMHS. Healthcare costs fell for all young people over the study, with a sharper decrease for those who fell through the gap.


Conclusions: Total healthcare costs fell for all participants, indicating that the intensity of mental health support reduces for all young people as they cross the CAMHS boundary, regardless of clinical need.


Clinical implications: It is important that alternative forms of mental health support are available for young people who do not meet the AMHS care threshold but still have mental health needs after leaving CAMHS.



  • Previous research has indicated that around a quarter of young people transition to adult mental health services (AMHS) after reaching the upper age limit of child and adolescent mental health services (CAMHS).
  • Young people with diagnoses of severe and enduring mental illness are more likely to transition, as are those who have previously attempted suicide or who are more severely ill when they reach the transition boundary.


  • To our knowledge, this is the first study exploring resource use and healthcare costs for young people after leaving CAMHS.
  • This study also indicated that only the most severely ill of young people with a diagnosis of anxiety or mood disorder, neurodevelopmental disorder or emerging personality disorder transition to AMHS.


  • Not all young people require ongoing mental health support after leaving CAMHS. However, there is a subsample of young people who do require ongoing support but do not meet the criteria for AMHS. It is important that other sources of support are available to meet the mental health needs of these young people.
Rebecca Appleton, Alastair Canaway, Helena Tuomainen, Gwen Dieleman, Suzanne Gerritsen, Mathilde Overbeek, Athanasios Maras, Larissa van Bodegom, Tomislav Franić, Giovanni de Girolamo, Jason Madan, Fiona McNicholas, Diane Purper-Ouakil, Ulrike M E Schulze, Sabine Tremmery, Swaran P Singh | 2023
In: BMJ Mental Health ; ISSN: 2755-9734 | 26 | e300814
Adolescents, Adults, Belgium, Croats, Diagnosis, Europeans, French, Germans, Great Britain, Health Care Costs, Italians, Longitudinal Study, Mental health, Netherlands, Predictors, Young Adults
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