In some countries, the practice of forensic psychiatry is confined to providing psychiatric evaluation to the court (Harding 1993). In England and Wales, forensic psychiatrists are involved in the assessment and treatment of patients who have been charged with an offence or convicted by a court and, since the 1959 Mental Health Act, patients may be transferred to forensic psychiatric units without being charged with any offence. Most of these patients would now be detained on Section 3 of the 1983 Mental Health Act, though a few may be subject to Section 2 of the same Act. Consequently, when the Reed Committee reported (Department of Health and Home Office 1992), it covered not only mentally abnormal offenders, but also ‘those requiring similar services’.

In reality, therefore, there is an overlap between general and forensic psychiatry rather than any sharp demarcation. It can indeed be arbitrary whether or not a patient in the community or a psychiatric hospital is charged with a criminal offence (James and Hamilton 1991; Cripps et al. 1995). Most patients admitted to regional secure units or Special Hospitals have previously received treatment in general psychiatric hospitals (Parker 1973; Cope and Ndegwa 1990; Murray 1996). Considerable tension may exist between general and forensic psychiatrists, and related health professionals, as to which patients are accepted for transfer into forensic psychiatric units, and then subsequently back to the general psychiatric sector, though liaison is better in some areas compared to others.