Psychiatry, molecular genetics and ethics: the new discoveries and the new issues.

Recent developments in molecular genetics are examined with particular reference to psychiatry. The new technologies available have allowed significant advances in the understanding of certain illnesses such as familial Alzheimer's disease and Huntington's chorea, and will provide powerful tools to explore many other important psychiatric illnesses. The area of genetic counselling is already characterized by complex ethical issues. We can expect that as the new technologies provide the prospect of positive germ line genetic engineering, these ethical issues will become more complex. It is important that psychiatrists prepare themselves for these future developments and take an active role in leading the debate.