Managing ambiguity: obsessive-compulsive disorder (OCD) and styles of reasoning in British clinical psychology, c.1948-1990

Obsessive-compulsive disorder (OCD) is a significant mental health disorder today. Despite its contemporary prevalence, this thesis argues that OCD is a relatively recent psychological phenomenon. It traces the formation of OCD through a number of crucial stages in British clinical psychology between 1948 and 1990 (the bulk of the work occurring in the 1970s and 80s), showing the substantial intellectual and practical work involved in creating a stable clinical category. Historians of psychiatry have historicised diagnostic categories, and Science and Technology Studies (STS) scholars have challenged the inevitability of core epistemological concepts in science (such as ‘objectivity’). This thesis brings these approaches together to show how OCD is a paradigmatic example of clinical psychology reasoning. It details the conceptual development of OCD, and how its components (compulsions, ruminations, intrusive thoughts, reassurance) were constituted by, and in turn reflect, the specific epistemological and methodological commitments of a small group of clinical psychologists working at the Maudsley and Institute of Psychiatry in South London, predominately Stanley Rachman. The final part centres on the work of Paul Salkovskis at the University of Oxford. The methods and research practices of Rachman et al, their mode of reasoning, was underpinned by an adherence to a specific notion of evidence- one that favoured experimentation, measurable outcomes, replication, and cost-efficient service delivery, whilst systematically devaluing questions of meaning. The conceptions of evidence adhered to by clinical psychologists, and their corresponding experimental/therapeutic interventions, were further shaped by institutional factors, professional rivalries, and broader sociopolitical contexts. The model of OCD, and the reasoning it exemplifies, have become institutionalised in British mental health care today with the rise of evidence-based medicine. In showing the contingencies and consequences of clinical psychology reasoning, this thesis ultimately opens up the space for alternative modes of thinking about obsessionality and psychic distress more broadly.