There are a number of possibilities for someone to become depressed. Some believe it is hereditary, some believe it was brought on by a traumatic event; others even believe they were born with it. Regardless of the cause, scientists have been searching for a possible cause of depression.
Time Magazine posted an article reveling a new study has confirmed that evidence of a particular gene involved in transporting serotonin, a brain chemical critical to mod, may play a role in triggering the mental disorder in some people.
Researchers led by Dr. Srijan Sen, a professor of psychiatry at University of Michigan, report in the Archives of General Psychiatry that individuals with a particular form of the serotonin transporter gene were more vulnerable to developing depression when faced with stressful life events such as having a serious medical illness or being a victim of childhood abuse. This inherited gene construction prevents the mood-regulating serotonin from being re-absorbed by nerve cells in the brain. Having such a low-functioning version of the transporter starting early in life appears to set these individuals up for developing depression later on. However, the exact relationship between this gene, stress, and depression is not 100% clear.
This is not the first study conducted on depression linked with genes. For the first time, in 2003, scientists confirmed the link between genes and environment in depression. This study involved more than 800 subjects. These individuals had the gene coding for the less functional serotonin transporter proved to be more likely to develop depression following a stressful life event than those with the more functional form of the gene. But in 2009, these findings were questioned. This analysis pooled 14 studies investigating the relationship between the serotonin transporter gene, depression and dress, and found no heightened risk of depression among those with different versions of the gene.
With controversy surrounding these new findings, Sen continued researching. He gathered all available studies on the subject, 54 total, which included data from nearly 41,000 volunteers. With significantly more data, this broader analysis concluded that the less functional form of the transporter gene does indeed confer a greater risk of depression when combined with stress. On top of these new results, Sen dug deeper into why the 2009 study found contradictory results. When re-evaluating their data, he found that when he limited his investigation to 14 studies, he found no relationship between the gene and depression. He believes these findings do not contradict the 2003 findings or latest results, but rather reflect a difference in the way the study was conducted. The 2009 study included stressful live events in the 14 studies, but did not incorporate other stressors such as childhood abuse or medical illness. The more complete set of 54 studies, which included these stressors as well, showed a boisterous interaction between the serotonin gene, stress and depression.
Sen continued to clear up all research to settle the story in order to move forward in uncovering the link between genes and depression. Putting these contradicting studies to rest, he hopes to look more broadly across the genome for more factors related to depression. “Ideally we would like to find a panel of different genetic variations that go together to help us predict who is going to respond poorly to stress, and who might respond well to specific types of treatment as opposed to others.”
Sen however stresses that this gene is only one player in the cast of genetic and environmental factors that contribute to depression. “All things considered, this gene is a relatively small factor, and for this finding to be clinically useful, we really need to find many, many more factors. Ultimately we may identify new pathways that are involved in depression to come up with new and better treatments.”
As someone who suffers from depression, I find comfort in knowing that depression is not the cause of a traumatic event or self-inflicted. Understanding that depression is a disease, just as much as diabetes is, helps ease possible shame or embarrassment. Educating others that depression is in fact a disease helps fight stigma surrounding mental illness. Hopefully, with continued research, researchers will uncover the root of depression. With this, they will be able to design successful treatment, and possibly even a cure.