The Link Between Genetics and Mental Illness
With mental health struggles finally being brought to light as the stigma behind depression and other psychiatric disorders lessens, many have been seeking answers to their long-awaited questions: why is this happening, and what can I do to alleviate my struggle?
Major depressive disorder manifests in a variety of ways and from various circumstances such as stressful life events. But what makes some people more prone to developing these mental illnesses than others? Genetics.
Human biology is far more complex that most give it credit for. When the average person thinks of genetics, overused punnet squares of hair color are brought to the forefront of their mind, but the visible, physical impacts of it barely scratch the surface. The brain is one such example of the convoluted implications of genetics. The way we process information, deal with emotions, and interact with the world are all linked to genes and their variants.
The Research
A study led by teams at Yale and UC San Diego collected data from more than 300,000 participants and a base of information—with over 1.3 million participants—from companies such as 23andMe to find 178 variants linked to depressive disorders. By comparing two sets of data, the researchers were able to find that, for the majority of tests, variants related to depression were replicated.
David Levey, a researcher at Yale, emphasized the positive results of the research, “Replication is a hallmark of good science, and this paper points to just how reliable and stable results from GWAS studies are becoming”
But what does this mean?
In short, these variants (discovered in the GWAS: genome -wide association study) were confirmed to cause a statistical difference in a person's chance to develop depression in their life. While depression can be caused by numerous external factors, those with a genetic predisposition to such mental disorders are more at risk. However, like other aspects of human biology, depression is defined by a complex combination of genetic traits as well as external impacts—nature and nurture. With almost 200 variants discovered, researchers are hopeful in finding more to be able to more elaborately explain this mental illness.
So What?
Concisely put: “One of the real goals of the research is bringing forward new ways to treat people suffering from depression,” says Dr. Murray Stein, a psychiatrist at UC San Diego.
Depression and other incurable mental disorders are treated with a wide variety of medications and therapies to improve quality of life. Thanks to newfound knowledge on these genetic traits, the horizons have widened. For instance, some genes discovered to be linked to depression are also linked to other body systems, bringing forth the opportunity of researching the effectiveness of different medications, which are typically used to treat other illnesses, for depression. An example of this can be seen in the depression-linked genes that impact the glutamate system and the drug—riluzole—which is currently being used to modulate glucose transmission in the brain and being researched as a potential antidepressant.
The underlying causes of mental disorders and their connections to the rest of the body are also being investigated with the many variants that may be linked to other anatomical systems. Through understanding the roles of these factors, even more targeted and specific treatments can be formed.
Levey says it best: “It’s really striking when completely different kinds of research converge on similar biology, and that’s what’s happening here.”
The Future
Like the rest of the brain, mental disorders are vastly complex, and we’ve really just begun our dive into the abyss. Through the discovery of hundreds—maybe even thousands—of variants, scientists can truly formulate preventative and treatment plans to more effectively alleviate the suffering of millions around the world. We’ve still got a long way to go until we fully understand the convoluted brain, but progress is progress.