Criminal insanity in 19th-century Ireland, Europe and the United States: cases, contexts and controversies.

The insanity defence has a lengthy, complex history. This article provides a concise, comparative background to the evolution of criminal insanity legislation and institutions for the mentally ill in the nineteenth century, with particular reference to Ireland and the United States. Three key themes are identified and explored: (a) the emergence of the insanity defence in the nineteenth century (e.g. the McNaughtan Rules); (b) conditions in nineteenth-century asylums and institutions for the 'criminally insane' (with particular reference to overcrowding, physical illness and asylum deaths); and (c) nineteenth-century considerations of criminal responsibility in women with mental illness (with particular reference to medical and judicial views of the relevance of menstruation, pregnancy and child-birth). These themes are explored through review of historical literature (with particular reference to the work of Dr. Isaac Ray, founding father of forensic psychiatry in the United States) and examination of previously unpublished archival material from the Central Criminal Lunatic Asylum, Dublin.