ABSTRACT
Depression is a common psychiatric disorder with a lifetime prevalence
as high as 12% in men and 25% in women. A recent review by the
World Bank has suggested that by 2020 depression is likely to be second
only to ischaemic heart disease as a cause of global health burden
(Murray and Lopez, 1996). Depression has been known to run in fam-
ilies since ancient times. Hippocrates, in ancient Greece, had noted the
parent-to-child transmission of melancholia. More recent family studies
have provided further evidence for this fact. Twin studies and adoption
studies have helped to clarify the relative contribution of genetic and
environmental factors in the causation of unipolar depression and
recent advances in molecular genetics now provide the tools needed to
identify genes influencing susceptibility.
