Richard Edney and Kate Ballard address the issue of how to punish offenders who have a mental disorder. The understanding of what mental conditions can be treated as matters in mitigation has tended to change over time. What appeared to be settled was that personality disorders could not be used on behalf of an offender to mitigate an otherwise just and proportionate sentence. That position has been changed by the five-member decision of the Victorian Court of Appeal in Brown v The Queen [2020] VSCA 212.