Abstract
This paper focuses on the second phase of the deinstitutionalisation of mental health care in which the development of community-based interventions are supposed to be implemented in local community mental health care systems. The challenge to sustainable implementation is illustrated by the Swedish case where the government put forward a national training program that sought to introduce Assertive Community Treatment (ACT) for people with severe mental illness. This study is based on document analysis and qualitative interviews with actors at the national, regional, and local levels covering a total of five regions and 15 municipalities that participated in the program. The analysis of the national experiences is put in relation to both research on public administration and policy analysis as well as to current research on implementation of evidence-based programs. The results showed a "drift" of the original model, which had already begun at the policy formulation stage and ended up in a large number of different local arrangements where only a few of the original components of ACT remained. We conclude that issues with implementation can only be fully understood by considering factors at different analytical levels.