It is not enough to say that a person has a personality disorder – even psychopathy – to explain their past violence or future harm potential. This keynote will address the various ways in which personality problems can, in some people, create the potential for violence, including self-directed harm. The presentation will begin with an overview of what we mean now (post the DSM-5 AMPD and ICD-11 developments) when we talk about personality problems, and the nature of the relationships possible between such problems and harmful outcomes. The keynote will consider some of the mechanisms by which violence may occur in individuals with this range of difficulties and how to differentiate that potential from the ways in which other mental health problems can create a risk of harmful behaviour. The presentation will conclude with some practical suggestions for capturing and managing personality problems through assessment and formulation.