The boundary between services for children and adolescents and adults has been identified as problematic for young people with mental health problems.

To examine the use and cost of healthcare for young people engaged in mental healthcare before and after the child/adolescent and adult service boundary.

Data from 772 young people in seven European countries participating in the MILESTONE trial were analysed. We analysed and costed healthcare resources used in the 6-month period before and after the service boundary.

The proportion of young people engaging with healthcare services fell substantially after crossing the service boundary (associated costs €7761 pre-boundary v. €3376 post-boundary). Pre-boundary, the main cost driver was in-patient care (approximately 50%), whereas post-boundary costs were more evenly spread between services; cost reductions were correlated with pre-boundary in-patient care. Severity was associated with substantially higher costs pre- and post-boundary, and those who were engaged specifically with mental health services after the service boundary accrued the greatest healthcare costs post-service boundary.

Costs of healthcare are large in this population, but fall considerably after transition, particularly for those who were most severely ill. In part, this is likely to reflect improvement in the mental health of young people. However, qualitative evidence from the MILESTONE study suggests that lack of capacity in adult services and young people's disengagement with formal mental health services post-transition are contributing factors. Long-term data are needed to assess the adverse long-term effects on costs and health of this unmet need and disengagement.

For people in mental health crisis, acute day units (ADUs) provide daily structured sessions and peer support in non-residential settings, often as an addition or alternative to crisis resolution teams (CRTs). There is little recent evidence about outcomes for those using ADUs, particularly compared with those receiving CRT care alone.

We aimed to investigate readmission rates, satisfaction and well-being outcomes for people using ADUs and CRTs.

We conducted a cohort study comparing readmission to acute mental healthcare during a 6-month period for ADU and CRT participants. Secondary outcomes included satisfaction (Client Satisfaction Questionnaire), well-being (Short Warwick–Edinburgh Mental Well-being Scale) and depression (Center for Epidemiologic Studies Depression Scale).

We recruited 744 participants (ADU: n = 431, 58%; CRT: n = 312, 42%) across four National Health Service trusts/health regions. There was no statistically significant overall difference in readmissions: 21% of ADU participants and 23% of CRT participants were readmitted over 6 months (adjusted hazard ratio 0.78, 95% CI 0.54–1.14). However, readmission results varied substantially by setting. At follow-up, ADU participants had significantly higher Client Satisfaction Questionnaire scores (2.5, 95% CI 1.4–3.5, P < 0.001) and well-being scores (1.3, 95% CI 0.4–2.1, P = 0.004), and lower depression scores (−1.7, 95% CI −2.7 to −0.8, P < 0.001), than CRT participants.

Patients who accessed ADUs demonstrated better outcomes for satisfaction, well-being and depression, and no significant differences in risk of readmission, compared with those who only used CRTs. Given the positive outcomes for patients, and the fact that ADUs are inconsistently provided in the National Health Service, their value and place in the acute care pathway needs further consideration and research.

Interventions and services for people with mental health problems can have broad remits: they are often designed to treat people with a variety of diagnoses. Furthermore, addressing mental health problems can have long-term implications for economic, social, and health outcomes. This represents a challenge for health technology assessment, for which long-term trial data can be lacking. In this review, we sought to identify how analysts have tackled this problem. We reviewed the methods used to extrapolate costs and outcomes for the purpose of economic evaluation where long-term trial data are not available.

We conducted a systematic review of the medical and economic literature evaluating long-term costs and outcomes for mental health interventions and services designed to treat or prevent more than two mental health conditions. We searched key databases including MEDLINE, Embase, PsycINFO, CINAHL, and EconLit. Two authors independently screened citations. Articles were excluded if they reported within-trial analyses or employed a time horizon of less than 5 years.

The search identified 829 unique records. No papers could be included in the review.

This review highlights the lack of research and understanding available to inform the appraisal of broad mental health interventions. In light of our findings, we consider the reasons for this lack of information and review relevant literature on the subject. Potential barriers to research in this context include: (i) challenges in understanding the value of broad mental health services, such as the mental and physical health nexus, intersectoral costs and benefits, and interpersonal impacts, (ii) methodological difficulties, such as data availability, patient heterogeneity, and the challenge of extrapolation, and (iii) parity of esteem. We make recommendations for resolving this problem with regard to funding, data collection, modelling methods, and outcome measurement.