Background
As clinical studies show, manifestation of psychiatric problems differs between adults on one hand and children and adolescents on the other hand. As a consequence, service planning for mentally ill children and adolescents need to take the specific needs and the evidence of interventions in child and adolescent psychiatry into account.

Health economic evaluations are a common tool to support service planning. They estimate costs and benefits of treatment alternatives. In the study we analyse the actual evidence on such evaluations in the field of child and youth psychiatry.

Method
A systematic literature search in medical and economic databases has been carried out to identify economic evaluations. Based on a hand search we added some single relevant studies as well as some background literature. We analysed the studies according to methodological characteristics and results by indication and by intervention. Furthermore the report contains an overview of the methods of cost calculation as well as modelling practices documented in the studies. This has been done to enlighten the range of existing instruments that are used in the field.

Results
Over an eligible period of 25 years we identified one single systematic review and 25 economic evaluations. Some indications, e.g. ADHD, as well as some interventions, e.g. cognitive behaviour therapy, are examined more often than others. Most of the studies are cost-effectiveness analyses. Compared to interventions in somatic medicine, most of the results show a low cost-effectiveness ratio. Hence, they are likely to be judged cost-effective. Most of the studies suffer a lack of transparency, especially in respect to information about cost surveys and modelling. Their transferability is limited because of their context-specificity.
In cost surveys the public payers’ or insurers’ perspective is the most common one. Apart from this, there are some instruments for cost analysis that reflect a broader perspective such as the ‘Client Service Receipt Inventory’. In addition to costs in the health sector it addresses services received in other sectors and private costs. .

Conclusion
Despite the fact that cost-effectiveness ratios in the overall evidence tend to be low, more transparent, country specific economic evaluations need to be done to establish financially sustainable services for mentally ill children and adolescents. Based on the evidence analysed in this report, some interventions and indications such as motivational therapy or addiction have hardly been examined on the level of economic evaluations.
In addition there is a lack of evidence in the fields of long term cost assessments and broader cost perspectives, considering sectors outside the health system.