[Molecular genetics of mood disorders].

Mood disorders are common diseases and cause a big burden on society, including suicide. Because there are many treatment resistant cases in mood disorders, it is very important to elucidate the pathophysiology of this condition to establish its prevention and its treatment. Genetic epidemiological studies have shown that genetic factors have an important role in the pathophysiology of mood disorders; therefore the molecular genetics studies of this condition have been extensively performed, such as positional approach (i.e., linkage study) and candidate gene approach (i.e., association study). Linkage studies have shown some candidate locations that have been reproduced in two or more studies, such as 1q21-42, 4p16, 10q21-26, 11p15, 12q23-24, 13q11-32, 18p11, 18q21-22, 22q11-13, Xp11, and Xq24-28. Most association studies have until now focused on the neurotransmitter system as a candidate molecule including serotonin transporter, serotonin receptors, dopamine receptors, tyrosine hydroxylase, MAO-A, COMT, and tryptophan hydroxylase. Moreover, phamacogenetic studies also have been carried out in this field to develop new drugs as well as personalized medicine. Future molecular genetic studies will find out the mood-disorder susceptible genes and open the gate to true treatment and prevention of this disorder as the Human Genome Project attains its goal.