The issue as to how to punish offenders who have a mental disorder has been a long-standing concern of the criminal law. The ‘understanding’ of what mental conditions or disorders can be treated as matters in mitigation has tended to shift and change over time. What appeared to be settled was that personality disorders could not, as a matter of principle, be used on behalf of an offender to mitigate an otherwise just and proportionate sentence. That position has been radically changed by the five-member decision of the Victorian Court of Appeal in Brown v The Queen [2020] VSCA 212. In this session presented by Richard Edney and Kate Ballard, Brown is explained and the implications of this significant decision are explored in detail.