A Breakthrough Global Study of Depression Finds 44 Genetic Variants Linked to the Disease

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Though depression affects an estimated 14 percent of the world’s population, scientists know very little about the underlying causes of the disorder, and that makes it incredibly difficult to treat. Even now, researchers are still debating whether common antidepressant medications even work at all, and if they do, why.

New research published in the journal Nature Genetics provides a big step in figuring out why some people suffer from depression while others don’t, identifying 44 genetic variants that are risk factors for major depression, 30 of which are new. They also found two regions of the brain that appear to be associated with the development of the disorder.

The study is the result of an international effort by more than 200 researchers involved with the Psychiatric Genomics Consortium. It looked at more than 135,000 cases of depression (both self-reported and clinically assessed) and almost 345,000 control cases. It’s the largest study on the genetic basis of depression ever done.

The researchers found that all humans carry some of the 44 risk factors identified. Some people carry more than others, putting them at greater risk for developing depression. They also identified the prefrontal and anterior cingulate cortices (both located at the front of the brain) as the regions of the brain probably linked with the development of depression.

Some of the risk factors the researchers identified are also involved in other psychiatric disorders, like schizophrenia, which isn't entirely surprising—a 2007 study from the Psychiatric Genomics Consortium found that people with depression, bipolar disorder, and schizophrenia as well as developmental disorders like ADHD and autism share the same variations in four locations in their genetic code.

By identifying genetic risk factors associated with major depressive disorder, the scientists hope to increase our understanding of why depression strikes some people and not others. "[M]ajor depression is a brain disorder," the researchers conclude. "Although this is not unexpected, some past models of [major depressive disorder] have had little or no place for heredity or biology." They firmly put to rest the idea that depression is entirely a matter of environment.

Environment certainly plays a role—the researchers found links between lower education levels and higher body mass index and depression risk as well—but genetics may impact whether someone whose circumstances put them at risk of depression actually develops the disorder. Depression is still highly stigmatized, which often prevents people from seeking treatment for it, according to several studies. Further understanding of the genetic underpinnings of the disorder may help counter negative perceptions of depression as a character flaw or a sign of laziness.

The study could eventually change how doctors treat depression. Many of the genetic variants identified by this study are linked to targets of current antidepressant medications, like serotonin. But the research may also lead to the development of new medications and therapies that could work for more people (current medications don't work for everyone) and potentially have fewer side effects than existing treatments.

The study partially relied on self-reported depression diagnoses, meaning there's some wiggle room in knowing whether those people are actually clinically depressed to the degree that a medical professional would diagnose. Further research will need to confirm that these genetic variants are indeed linked to depression. There are likely even more gene variants related to depression risk, as well, but they might have too small of an effect to be identified by this study. The researchers hope to continue their work to understand the links between environmental stressors, genetic variations, and depression risk in the future.

Archaeologists Uncover World's Oldest Known Brewery in Israel

People have been knocking back beers for 13,000 years, according to new archaeological findings out of the Middle East. As Science magazine reports, evidence of wheat and barley-based beer was found inside stone mortars carved into the floor of a cave near Haifa, Israel.

The Raqefet Cave was used as a burial site by the Natufians, a group of semi-nomadic hunter-gatherers who were also responsible for the world’s oldest known bread, which was discovered in Jordan in July. These findings challenge previous evidence that traced the origin of beer back just 5000 years.

Beer was also previously believed to be merely a by-product of bread-making, but archaeologists say that isn’t necessarily the case. Instead, researchers believe beer may been served during ritual feasts “to venerate the dead and/or to enhance group cohesion among the living,” researchers wrote in their paper, published in the Journal of Archaeological Science: Reports.

Remarkably, the Stanford University researchers who made this discovery weren't even looking for evidence of alcohol. “We did not set out to find alcohol in the stone mortars, but just wanted to investigate what plant foods people may have consumed because very little data was available in the archaeological record,” Li Liu, a professor of Chinese archaeology at Stanford, said in a statement.

Researchers theorize that beer brewing may have inspired the Natufians to cultivate cereals in the region, but it’s not currently known whether beer or bread came first. The mortars dug into the cave floor were reportedly used for storing and pounding wheat and barley, as well as brewing beer.

The beverage wasn’t exactly what we know as beer today, though. According to the BBC, the prehistoric beer was “gruel-like” and similar to porridge. It was likely weaker than modern beer, too.

[h/t Science]

Newly Uncovered Galileo Letter Details How He Tried to Avoid the Inquisition

Galileo Before The Papal Tribunal by Robert Henry. Hulton Archive, Getty Images
Galileo Before The Papal Tribunal by Robert Henry. Hulton Archive, Getty Images

Galileo Galilei was one of the Roman Catholic Inquisition’s most famous targets. As a result of his outspoken support for the theory that all the planets, Earth included, revolve around the Sun, the Catholic Church charged him with heresy and he spent the last years of his life under house arrest. Galileo was well aware that he was on the Church’s hit list, and a newly discovered letter shows that at one point, he tried to tone down his ideas to avoid persecution, according to Nature and Ars Technica.

The letter in question, written in 1613, solves a long-held mystery for Galileo scholars. It was found in the library of the Royal Society, where it has been for at least 250 years.

Galileo’s beef with the Catholic Church came about because of his support for heliocentrism—the idea that the solar system centers around the Sun—as advocated in Nicolaus Copernicus’s book De Revolutionibus. Galileo’s scientific writings clearly endorsed Copernicus’s theory of the world, including in personal correspondence that was widely disseminated, and in some cases, he directly questioned the scientific merit of Biblical passages.

In 1613, Galileo wrote to a friend and former student named Benedetto Castelli who was then teaching mathematics at the University of Pisa. The letter was a long treatise on Galileo’s thoughts on Copernicus’s ideas and religion, arguing that science and astronomy should not be overpowered by religious doctrin . (He would later expand this into his Letter to the Grand Duchess Christina.) As with many of Galileo’s writings at the time, the letter was copied and disseminated widely, and eventually, a friar named Niccolò Lorini forwarded it to the Inquisition in Rome in 1615.

This is where things get tricky. Galileo claimed that the version of the letter Lorini sent was doctored to be more inflammatory. He sent a less controversial version of the letter to a friend, saying that it was the original document and should be forwarded to the Vatican, essentially to clear his name. But scholars have never been able to be totally sure if he was telling the truth about the letter being doctored.

This newly discovered letter suggests that he was lying, and that he himself was looking to tone down his rhetoric to appease the Catholic Church and keep authorities from quashing the spread of heliocentric ideas. The original copy found in the Royal Society archives shows changes to the wording in what appears to be Galileo’s handwriting. The seven-page letter, signed “G.G.,” includes changes like swapping the word “false” for the more slippery “look different from the truth,” changing “concealing” to “veiling,” and other edits that seek to tone down the rhetoric that inflamed Church leaders. The wording and handwriting corresponds to similar writing by Galileo at the time. Based on this finding, it seems that Galileo did seek to make his ideas more palatable to the Catholic Church in the hopes of escaping persecution by the Inquisition.

Discovered on a research trip by science historian Salvatore Ricciardo of Italy's University of Bergamo, the letter may have been overlooked in the Royal Society archives because it was cataloged as being dated October 21, 1613 rather than the date it actually bears, December 21, 1613. However, it’s unclear how it came to the Royal Society in the first place. The document is the subject of a forthcoming article by Ricciardo and his colleagues in the Royal Society journal Notes and Records, according to Nature.

The minor changes Galileo made did not successfully hold off the Church’s crackdown on heliocentrism. In 1616, the Inquisition ordered Galileo to stop teaching or defending the theory, and several of his books were subsequently banned. He would stand trial again almost two decades later, in 1633, on suspicion of holding heretical thoughts. He was found guilty and sentenced to house arrest, where he remained until his death in 1642.

[h/t Ars Technica]

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