BackgroundIntroduction of guidance by the National Institute for Health Research has led to an increase in participation by people with ‘lived experience’ of mental health problems. However, some researchers have questioned the extent to which involvement has been meaningful, expressing concerns that involvement is impeded by the structure and culture of academia. A prior review of literature to 2016 provided little evidence of active engagement.AimsTo find out from published literature how patient and public involvement in designing and or conducting research has been used in forensic mental health settings, prisons or probation since the last review period.MethodsA systematic scoping review of research published in academic journals between 2016 and February 2023 was completed using terms for research activity, involvement of people with experience of receiving services and health or justice systems to search three databases: MEDLINE, EMBASE and PsycINFO. We used the Guidance for Reporting Patient and Public Involvement in Research Tool to support data extraction and to summarise our own service user involvement in this study.ResultsFrom 675 unique titles retrieved, 17 were eligible for inclusion, covering 16 unique studies. Most of the included research was by/with people who had prison experience. Only two studies had been conducted by/with people who had experience of secure hospital wards/forensic mental health services. Details of how people with lived experience had contributed to the research were scarce, but in 8 studies they had been involved throughout and included in the authorship group.ConclusionWhilst this review identifies pockets of good practice, meaningful engagement in forensic mental health research seems to remain rare, at least as reported in papers published in academic journals. Further research is required into whether this reflects real limits on inclusion, as we suspect, or such full integration that such reporting is not regarded as necessary or desirable, which we doubt. We urge journal editors to routinely ask authors to include information about how people with lived experience have been involved in any published research and the nature and extent of the influence they had. This may help to develop the evidence base and guard against tokenistic involvement.