Connection found between gene and depression

Prof. Son Hyeon
Hanyang University

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By Kim Bo-eun

A research team discovered a close link between a gene in the brain and depression, opening the way for a more effectual remedy for the mental illness.

The Ministry of Education, Science and Technology said Tuesday that the team led by Hanyang University biomedical science professor Son Hyeon found that a gene called neuritin plays an important role in regulating depression, affected by the activity of hippocampus neurons in the brain.

The discovery was the result of four years of study on the behavior of white mice which developed depression. The hippocampus is the part of the brain that is involved in forming memories, organizing and storing information.

The findings were published in the June edition of "Proceedings of the National Academy of Sciences (PNAS)", a renowned international science journal.

"It is significant that we have found a connection between depression and neuritin, which becomes more active stimulated by neurons", said Son.

"The information will be utilized when developing a new anti-depressant with a better efficacy".

According to the Health Insurance Review and Assessment Service, 510,000 Koreans currently have a depressive disorder. The figure is 20 percent up from 2007.

Korea also has shown the highest suicide rate among member states of the Organization for Economic Cooperation and Development (OECD). Suicide is closely linked to depression.

The breakthrough in research that has found the link between the gene and depression is likely to have a positive effect on the treatment of the increasing number of people suffering from depression.

Depression is a mental disorder that is widespread among the public, regardless of age and gender. The disorder had been found to occur when the function and structure of the neuron in the hippocampus contracts.

However, there had been no evidence on how the phenomenon was actually related to depression and what kind of effect the depression medicine had.

Based on the fact that neuritin boosts the growth of neuritis, the team had set the hypothesis that the lack of neuritin causes depression and when a large amount is produced, the disorder is alleviated.

The team had let the white mice develop chronic stress depression by providing two types of aversive stimuli daily for 35 days. The stimuli included trapping the mice in cold water and not giving food.

The mice were found to be more immobile than other unaffected mice in situations in which they were trapped. This reflected that they had less will to try to escape, due to the depression that was developed as a result of stress.

Then its researchers dissected the mice and found that the neuritin genes had decreased due to depression. They also found that neuritin had been restored to normal levels once anti-depressants such as Prozac had been injected into the mice.

Depressive disorder develops as one shows symptoms such as a low mood and the loss of interest and pleasure in once enjoyable activities. It causes various cognitive, mental and physical symptoms and results in a decline in the ability to perform everyday activities.