We are on the verge of major advances in understanding the pathophysiology of major mental illnesses – including the likely discovery of several susceptibility genes for these conditions. For many this holds the prospect of a future in which improved prevention and better treatments will end the terror these conditions hold over so many lives (Farmer & Owen, 1996; Jones & Craddock, 1997, 1998). For others the vision is of a ‘brave new world‘, our futures mapped from birth by the genetic hand we have been dealt and in which those with mental illness will suffer increased stigma and discrimination (Rose, 1998). This debate (McGleenan, 1995) occurs in the dark shadow cast by the eugenic movements of the 19th and early 20th century (Galton, 1943) and the horrors to which they led (Hanauske-Abel, 1996; Seidelman, 1996). As we leave the decade of the brain and enter the new millennium it is an appropriate point to ask what advances are likely to occur and to consider the moral and ethical issues that will undoubtedly arise.