Towards a health-informed approach to penal reform? Evidence from ten countries into support and treatment from the earliest point at which they are involved with police. At the other end of the spectrum, we discuss the largely hidden problem of prisoners who develop dementia and other age-related cognitive impairments – an inevitable consequence of the use of ever-longer sentences in many countries. Taking a public health approach to penal reform means recognising the way in which societal disadvantage and marginalisation raise the risk of involvement in criminal justice processes. It means seeking to address that risk by providing more effectively for health needs in the community, particularly those linked to mental health and drug or alcohol problems. It also means that, for those reduced numbers for whom custody is inevitable, there is proper access to healthcare, screening and treatment; prisoners’ health and wellbeing are promoted; and harm reduction measures are in place to minimise risks to the health of prisoners, staff and the wider public. As Justice Cameron makes clear in his Foreword, the state of a country’s prison system is ultimately the result of political choices. It will take considerable political will to put in place the policies needed to end our over-reliance on criminal justice interventions and accept that other approaches, focused on tackling social injustice and health inequality, are more likely to reduce crime and improve public health. vi