In May 2006, the Government formally approved the development of a new national forensic mental health facility at Thornton Hall, Co Dublin, adjacent to the new prison. The new hospital facility will provide a therapeutic, forensic psychiatric service to the highest international standards, in a state-of–the-art building. This decision was consistent with "A Vision for Change" — the report of the Expert Group on Mental Health Policy, which recommended that the Central Mental Hospital (CMH) should be replaced or remodelled to allow it to provide care and treatment in a modern, up-to-date humane setting and that the capacity of the CMH should be maximised.
The redevelopment of the CMH will constitute a separate capital development project independent of the prison complex to replace Mountjoy Prison, and will be owned and managed by the Health Service Executive (HSE). The development of the new CMH is the responsibility of the HSE and at present, a project team is progressing the development of the new hospital. The new hospital will be built on its own campus and will retain its identity as a distinct therapeutic health facility with a separate entrance and address to the prison complex.