Drug use and its associated harms are substantially more prevalent among people in contact with the criminal justice systems, including those currently living in prison and those with a history of imprisonment, compared to the general population (Dolan et al., 2015). In many countries, problematic drug use is viewed primarily as a criminal justice issue rather than a health problem. Consequently, prison-based harm reduction interventions, such as opioid agonist treatment and needle and syringe programs, are often either unavailable or implemented with low coverage and quality (Dolan et al., 2016). After release, many may continue to use illicit drugs, increasing their risk of reincarceration and premature death due to overdose. Socio-cultural issues such as stigma and discrimination, poverty, and lack of access to healthcare services further exacerbate these risks (Kamarulzaman et al., 2016).Despite its importance, data on drug use and associated harms among people in contact with the criminal justice systems are scarce. Moreover, the available publications are often outdated or lack quality. To address this issue, the Journal of Community Psychology has published a special issue titled "Drug Use and Associated Harms Among People in Contact with the Criminal Justice System." This special issue comprises eight manuscripts that explore various aspects of substance use and its associated harms among this vulnerable population. Duke et al. (2024) examine drug-related deaths and associated factors in prisons in England and Wales from 2015 to 2020. The study highlights the complex interplay between consumed substances, individual characteristics, situational factors, and the environment in explaining substance-related mortalities within prison settings. A key finding of the paper is the increasing significance of new psychoactive substances and their contribution to mortality in prisons. Vroom and Johnson (2024) investigate the relationship between parental supervision and opioid misuse among 79,960 justice-involved adolescents in Florida, USA. The findings indicate that parental supervision can be an effective protective factor against opioid misuse in this population. The authors recommend that consistent parental supervision be considered a crucial element in the design and implementation of opioid misuse prevention and treatment programs. Amaya et al. (2024) evaluate the availability, accessibility, and delivery models of oral health services in prisons, worldwide. Oral health services are particularly important for incarcerated individuals, who are often exposed to significant risk factors such as substance use. This global systematic scoping review highlights the widespread lack of availability, accessibility, acceptability, and quality of oral health services in prison settings, as well as the notable scarcity of published data on this topic. Dogan-Dixon et al. (2024) examine the impact of vicarious trauma (e.g., witnessing an assault with a weapon or experiencing a sudden accidental death) and perceived social ...