When this journal entry was made I had already been working with people in prison for a number of years — something I continue to do. Back in 1995, diagnostic work was not my primary focus, nor was the prevention of self-harm and suicide, yet each of these was embedded in wider ethnographies. The reception process described above, where prison staff were concerned with identifying perceived vulnerability at a specific point in time, is one example of this. Another example from daily prison life could be a comment by a member of staff that someone appeared to be ‘looking better’ or ‘needed to be kept an eye on’. Diagnosis is still not my primary concern, but as I consider the extent and depth to which I have become familiar with the prison system and its members, it appears that aspects of diagnosis run like threads through many prison activities and practices. This is no more apparent than in prison officers’ capacity to manage prisoners’ perceived ability (or inability) to survive and cope with institutional life.