This thesis critically examines serious mental illness and the provision of care within prisons in England and Wales. It investigates how services for prisoner‑patients with complex mental health needs are organised and delivered through a qualitative, two‑part design: an analysis of 44 HM Inspectorate of Prisons reports from inspections during the COVID‑19 pandemic, and semi‑structured interviews with 51 participants – including prisoner‑patients, prison staff, and secondary mental healthcare professionals – across four prisons.

Prisons are not designed as therapeutic environments, yet the prevalence of mental illness among imprisoned populations far exceeds that of the general population. Prison conditions often deteriorate mental health, while institutional constraints limit responsive and appropriate care. Existing research highlights these challenges but has not fully explored how individual actors, organisational practices, and the wider institutional context interact in shaping care for those with serious mental illness. This thesis addresses that gap by bringing together the perspectives of those who live and work in prisons, offering new insights for policy and practice. As no comparable study has been undertaken in England and Wales, this research makes an important contribution.

Findings show that prisoner‑patients with serious mental illness experienced mental health care as inconsistent, fragmented, and difficult to access. Support often depended on staff recognition and was restricted by institutional routines. While some positive clinician relationships existed, most care was crisis‑driven, under‑resourced, and constrained by environments that limited communication and autonomy. Prison and healthcare staff frequently felt overwhelmed, underprepared, and morally strained, diminishing their ability to deliver humane and effective care. Overall, provision was highly variable and often failed to meet basic needs.

The thesis argues for a reimagining of prison mental healthcare grounded in the experiential knowledge of staff and prisoner‑patients. A more relational, needs‑led, and compassionate interagency approach, supported by improved resources, is essential for achieving meaningful and humane reform.