Groundbreaking Research On Genetic Risk Factors For Depression Closes In On Solving The 'Nature Vs. Nurture' Debate

The study was a global collaboration between 200 scientists from 161 institutions worldwide!

What Causes Depression? Genetic Research Approaches Answers To The Nature Vs Nurture Debate Unsplash: Yeshi Kangrang

What causes depression? I certainly wish I knew, and frankly, so do most brain science and genetics experts. As of now, unfortunately, neuroscience and psychiatry have no clear answers, but a recently published, ground-breaking global study found at least 44 genes associated with risk factors, perhaps moving us closer than ever to ending the nature vs nurture debate once and for all.

Before I explain further, however, I must say that only time math doesn't annoy me, stress me out, and/or make me feel inadequate is when it's being used in relation to discussions about mental health conditions like depression.



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Ask me to figure out who owes what when eighteen of my closest friends and I go out to dinner and I'm likely to scream "fire" and flee in a panic, but ask me how many people in the United States suffer from clinical depression (aka major depressive disorder) in any given year, and I will gladly start spouting off those numbers

Since you asked, the most recent numbers out of the Centers for Disease Control and Prevention (CDC) say that nearly one in ten people living in the U.S. (8.1 percent) will experience at least one depressive episode, with nearly twice as many instances occurring among women (10.4 percent) than among men (5.5 percent). And if either of your parents or one of your siblings have depression, your chances of experiencing it yourself increase threefold.


I like to think about those numbers on days when it feels like I'm utterly alone and solely responsible for my own interminable sorrow.

"See, Becca," I can tell myself, "that person you just passed in the grocery store, she could be depressed, too!"

Focusing on the numbers has always felt much more satisfying to me than focusing on the science of it all, because for decades now, scientists have speculated about the specific link in the human genetic code that makes depression inheritable, and for all of their efforts, they have reached no clear conclusions. This lack of certainty left the doors opened wide for the seemingly endless debate about what really causes depression, i.e., is it nature or is it nurture?


I'm a control freak, so I don't like thinking that anything about my biological design as a human being is somehow beyond my control, which means the whole "nature versus nurture" argument is a hard one for me.

Have I experienced a lot of bad stuff over the course of my time as a person on this planet? Sure!

Am I also the child of parents who have depression? Yup!

Which is exactly why it's always been easier for me to focus on those numbers — those nearly one in ten people who are just like me — than it is to focus inward on whether and how either my DNA and/or my past may have contributed to making me the way that I am today.

That said, the findings of brand new research into "the genetic basis of major depression" were published on April 26 in Nature Genetics, and learning about the results has me thinking about my depression in a way that finally doesn't terrify me!



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Notably, the study was undertaken as a global collaboration between 200 scientists from 161 institutions worldwide, co-led by Patrick F. Sullivan, MD, from the University of North Carolina School of Medicine and Naomi Wray, PhD, from the University of Queensland in Australia. Their methodology involved"a meta-analysis of more than 135,000 people with major depression and more than 344,000 controls."

As reported in the Guardian, the researchers successfully identified "44 genes, out of the 20,000 genes comprising the human genome, which contribute to the transmission of risk for depression from one generation to the next."

The hope of those involved in the study is that as they approach new and exciting ways of understanding how our genes carry and transmit depression, they will develop new ways to treat and possibly even prevent the crippling mental health disorder.


“This study is a game-changer,” Sullivan said.“With more work, we should be able to develop tools important for treatment and even prevention of major depression.”

“We show that we all carry genetic variants for depression, but those with a higher burden are more susceptible,” Wray added. “We know that many life experiences also contribute to risk of depression, but identifying the genetic factors opens new doors for research into the biological drivers.”


Another significant finding from this study is that "many of the risk genes for depression also play a part in the workings of the immune system."

Dr. Edward Bullmore, author of the Guardian piece and the head of the department of psychiatry at Cambridge University explains further, "There is growing evidence that inflammation, the defensive response of the immune system to threats such as infection, can cause depression. We are also becoming more aware that social stress can cause increased inflammation of the body. For decades we’ve known that social stress is a major risk factor for depression. Now it seems that inflammation could be one of the missing links: stress provokes an inflammatory response by the body, which causes changes in how the brain works, which in turn cause the mental symptoms of depression."

And while there are no definitive answers yet as to the exact cause of depression, Bullmore believes "a deeper understanding of the genetics of depression will lead us beyond the question we started from: is it nature or nurture, gene or environment? The answer will turn out to be both."



RELATED: Depression Is Not A Choice


Rebecca Jane Stokes is a writer living in Brooklyn, New York with her cat, Batman. She hosts the love and dating advice show, Becca After Dark on YourTango's Facebook Page every Tuesday and Thursday at 10:15 pm Eastern. For more of her work, check out her Tumblr.