• children's mental health;
  • dissemination and implementation science;
  • evidence-based treatments;
  • science-practice gap

It has been proposed that one way of strengthening the effects of evidence-based treatments for youth in service clinics is to improve treatment integrity in these settings. Four assumptions related to this recommendation are evaluated in light of findings from effectiveness studies. The absence of evidence on links between treatment integrity and treatment outcome in effectiveness trials makes it difficult to estimate the potential benefits of many of the proposed quality control strategies. Incremental changes in methods to improve treatment integrity in service clinics must be considered in the context of structural barriers to implementation.