This thesis explores the way that policy has worked in UK mental health services, over the last twenty years. It constructs a framework for analysing three stages of policy making: namely policy initiation, policy formulation and policy implementation. Three levels of policy activity are also identified; these are located at the Macro, national level, the Meso, district health authority (DHA) level and the Micro, provider level. A matrix is then built up that facilitates an exploration of policy activity within and between these stages and levels. The study looked at the policy activity of managers and civil servants in the Department of Health, four DHAs and four provider units, as well as two mental health pressure groups. Research methods included participant observation, interviews, documentary analysis and questiormaires. The main findings of the study are that, historically, no level has held a monopoly on power or influence in the policy process, that the hitherto unsung role of the Meso level has been crucial for policy success, and that managers' abilities to shape their organisations decline above the Meso level. Since a new Labour Government came to power in 1997, however, the Macro level has begun to dominate the policy process. The ensuing 'top down' approach to policy formulation is ensuring uniformity of service, but may be stifling creativity. Policy activity is becoming less than the sum of its parts.