This thesis comprises three chapters: a literature review, an empirical paper and a reflective paper. The literature review evaluates papers describing the impact on staff of changes to mental health organisations in United Kingdom (UK). The different changes to the organisations are considered and the factors influencing change are identified alongside a critique of the identified papers. Different theories explaining the processes of organisational change are provided. The change theories, combined with the findings from the papers, are appraised and amalgamated to propose a model for organisational change in mental health services. The empirical paper reports on a grounded theory exploration of clinical psychologists as multi-disciplinary team (MDT) managers in National Health Service (NHS) mental health services. Positive professional experiences of leadership are associated with a move to MDT management. The decision to move to management ranges from a concrete early career decision to a perception that the organisation requires the participant to move into management. The steps to pursue management roles and the barriers faced are outlined. The central concept of participants’ experiences of being a manager is how they construct their identity and how this is shaped by interaction with the organisation and individuals. In addition, the way participants view themselves and are viewed by others was shaped by the medical model, service user focus, threat and time. These findings are linked to narrative models of identity and discussed in the context of existing literature on psychologists and leadership. The reflective paper explores the experience of conducting the research, specifically overcoming the barriers of gaining ethical approvals and recruitment and understanding how psychological defences can impact on the research journey. As this paper includes consideration of personal experiences and psychological defences it is written in the first person. The journal targeted for the literature review is the Journal for Change Management. The journal targeted for the Empirical Paper is the British Journal of Clinical Psychology.