Genetics of affective disorders.

Studies of the mode of inheritance of affective disorders have been reviewed. The overall picture which emerges does not seem to involve specific modes of inheritance. Linkage studies based on the single gene hypothesis, support X-linkage for a bipolar variant, as well as possible linkage to chromosomes 6 and 11. The more recent approach of linkage studies using large numbers of RFLP markers scattered throughout the genome looks promising, though it may still give rise to misinformation. Several confounding factors have been suggested such as genetic and phenotypic heterogeneity, as well as the lack of well defined diagnostic criteria.