Genetic Trigger of Depression Discovered
Researchers at Yale University released in an article to the journal Nature Medicine on October 17, 2010 the finding that they have discovered a genetic trigger to depression. This finding could prove very fruitful as it would enable scientists to form a new class of antidepressants that target this gene.
Depression Statistics in the United States
Depression is a common illness in the United States, afflicting around 18.8 million adults or 9.5 percent of Americans ages 18 and older. According to the CDC, depression costs billions of dollars in treatment, loss of productivity, workers’ compensation, and mortality. Though nearly twice as many women are diagnosed with the illness than men, depression occurs in all segments of society - all races, all socio-economic backgrounds, and all geographic backgrounds. Approximately 3.4 percent of people with depression end up committing suicide. A study by the World Health Organization and the World Bank found that unipolar major depression is the leading cause of disability in the US. The implications of this study to the current economy are vast.
What Exactly is Depression?
Major depression is a mental disorder characterized by low mood, accompanied by low self-esteem, and a pervasive lost of interest in activities that normally induce pleasure. The illness affects people in various areas of life including work or school, eating habits, family interactions and one’s general health. Unlike illnesses such as Diabetes or Heart Disease, there is no laboratory test that can identify depression.
Patients in treatment for depression are typically treated with a combination of talk therapy and medications like SSRIs (selective seratonin reuptake inhibitors), MAOIs (monoamine oxidase inhibitors), TCAs (tricyclic antidepressants), and TeCAs (tetra cyclic antidepressants). A minority of patients who are unresponsive to these other treatments are given electroconvulsive therapy (ECT), a treatment requiring a short-acting general anaesthetic, which then incurs a larger risk to the patient.
It has been very difficult for scientists to pin down the causes of depression. Many believe there are multiple physiological processes involved in depression, leading to different treatments working on different patients. Proposed causes of depression include not only these psychological factors, but also psycho-social, hereditary, evolutionary, and biological factors. As many as 40 percent of depressed patients remain unresponsive to the current medical treatments of depression.
MKP-1 Gene May Indicate a Higher Risk of Depression
Illustration of a Gene
In the Yale study, scientist Ronald Duman and his team did whole genome scans on tissue samples from 21 deceased individuals who had been diagnosed with depression and 18 deceased individuals who did not have the illness. Their findings revealed that a gene called MKP-1 was more than twice as prevalent in the depressed brain tissue samples. Duman and his team also found that when MKP-1 was knocked out in mice they were more resilient to stress, while when the gene was activated in the mice the results were symptoms that mimicked depression. Previous studies have shown that the molecular pathway inhibited by excessive amounts of this MKP-1 gene is involved in promoting the survival and function of nerve cells, which seems to support this new study.
Finding a Genetic Connection to Depression May Offer New Treatment Options
These findings could lead to new medical treatments for depressed patients who are otherwise resistant to medications for depression that targets the MKP-1 gene. These novel antidepressants could do away with more radical treatments like ECT and decrease the need for hospitalization of individuals dealing with depression. This could also have as great effects as increasing the average lifespan of someone with depression and could lower the number of people needing disability, and, thus, have an impact on the economy on many levels. Though the findings of this study are just the beginning, many people are optimistic that the research done by Duman and his colleagues could have great impacts on depression both in the US and the world.
Image sources: Minipic,
Gene illustration,
Woman with Depression
