Depression is considered a mental health disorder and a serious affliction when symptoms become severe. A new study points to a gene that may play a role in the development of depression, and can alter mood and stress when activated.
This gene, discovered by a team of researchers at the University of Maryland, can either protect a person from stressors, or it can do the complete opposite and trigger a downward spiral. It all depends on how active the gene is, but the gene plays a pivotal role in either case.
The findings were published in the Journal of Neuroscience and authored by the team led by Dr. Mary Kay Lobo. Lobo is an assistant professor in the Department of Anatomy and Neurobiology.
“This study really shines a light on how levels of this gene in these neurons affects mood,” said Lobo. “It suggests that people with altered levels of this gene in certain brain regions may have a much higher risk for depression and other emotional disorders related to stress.”
The gene, known as Slc6a15, works within specific neurons in the brain. Specifically, Lobo and her team focused on the nucleus accumbens, which plays a large part in the reward center of the brain. These neurons are activated after pleasant experiences, such as enjoying a romantic dinner or sharing a drink with friends. Having depression means that the reward center of the brain almost shuts down and these neurons do not become activated. This is known as anhedonia, causing the depressed individual to never feel a pleasurable response.
To gauge the role of this gene, the researchers studied mice that were likely to have depression: mice that no longer ate the food they previously enjoyed, or withdrew from “social” situations involving larger, more aggressive mice. When in these stressful situations, the researchers found that the Slc6a15 gene was significantly lessened. However, when these mice were supplied exogenously with higher levels of Slc6a15, their response to stress was much stronger.
After animal trials, the team examined the Slc6a15 levels in depressive humans. They looked particularly at the brains of people who had a history of major depression or had already committed suicide. Among these test subjects, they saw that the levels of Slc6a15 were markedly reduced. This confirms that the gene does play a role in both animals and humans, although the scientists cannot confirm exactly how Slc6a15 acts in the brain.
Lobo and her team hope that this research will lead to further study, and potentially even the creation of therapeutic treatments that target this “depression gene.” This also builds on previous research that confirms the role of Slc6a15, providing more insight into the workings of the brain, and leading to a more developed knowledge of depression and how it can be treated.