The present article reviews the recent molecular findings in mood disorders. Results of linkage and association studies are discussed in regard to the main limitations of these approaches in psychiatric disorders. On the whole linkage and association studies contributed to the localisation od some potential vulnerability genes for Bipolar disorder (BP) on chromosomes 11, 4, 21 and X. The hypothesis of anticipation in mood disorders is also considered in light of interesting results with trinucleotide repeat expansions.