The problem of personality disorders is “central” to the idea of criminal responsibility; this problem must therefore be analysed carefully using validated concepts, and the basis for these concepts should be reviewed with an eye to the consequences they can have for psychiatric and psychological reports. The phrase “personality disorder” brings into question of the very concept of personality, and of the use of this concept as a way of drawing exclusions and creating norms on the basis of interpersonal differences. Personality disorders raise questions of mental illness, in which the concept of personality disorders is a gap that is hard to ignore. Clinicians use this concept daily, but this use often arises from an interpretation on their part that may reflect a lack of understanding of the Other; an Other who does not share the same social values and norms. It is therefore necessary to ensure that we do not make excessive use of a psychological phenomenon whose validity remains to be established, so that it can be a tool for interpretation, and consensus-based guidelines should be created.