The author analyses how debate over the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders has tended to privilege certain conceptions of psychiatric diagnosis over others, as well as to polarise positions regarding psychiatric diagnosis. The article aims to muddy the black and white tenor of many discussions regarding psychiatric diagnosis by moving away from the preoccupation with diagnosis as classification and refocusing attention on diagnosis as a temporally and spatially complex, as well as highly mediated process. The article draws on historical, sociological and first-person perspectives regarding psychiatric diagnosis in order to emphasise the conceptual—and potentially ethical—benefits of ambivalence vis-à-vis the achievements and problems of psychiatric diagnosis.