[Genetic factors of depressive risk]

Since 1987, several sensational publications resulting from work performed with the new strategies of modern genetics--epidemiological genetics and molecular biology--have shed new light on the importance of genetic vulnerability factors in determining certain forms of mood disorders. The technical progress of genetics allied with the advances made in diagnosis now enable the testing of new theories on the etiopathology of thymic disorders. A considerable effort is now being made internationally and in Europe to develop the applications of molecular biology in order to clarify--at least partially--the role of genetic vulnerability factors in the etiopathology of mood disorders. In the relatively near future, standardising the methodology of linkage and association studies, and even the application of other more complex methods of analysis should lead to the nullification or confirmation of the presence of such factors on the short arm of chromosome 11 and on the long arm of the X chromosome, and should lead to the systematic detection of their presence on the entire genome. It should then be feasible to outline the genetic breakdown of mood disorders, particularly bipolar disorders, since some families seem to be linked to chromosome 11, others to X, and others, doubtless still more numerous, linked to other chromosomes. The different studies on genetic linkage performed these last four years will be presented and discussed with special emphasis on the factors which may explain the non-replication of certain studies.(ABSTRACT TRUNCATED AT 250 WORDS)