While the recreational use of marijuana is usually associated with a more peaceful mental state, scientists just a made a surprising discovery.
As detailed in a meta analysis of cannabis-related studies published last month in the journal Psychological Medicine, a team of scientists in the UK discovered a significant link between cannabis use and an “increased risk of violence.”
The headline finding was that they found cannabis users were statistically more likely to be the perpetrators of violent acts. They also found that the use of the drug — particularly among women and mixed-gender cohorts — was “significantly associated with an increased risk of becoming a victim of violence” as well.
While it’s a classic case of correlation, not causation — the researchers stop far short of suggesting the drug directly motivates users to be more violent as we’re far from reaching a scientific consensus on the matter — the findings “underscore the importance of addressing this issue at both a societal and clinical level,” according to the paper.
In other words, it’s a highly nuanced and complex relationship with plenty of other factors at play.
“As a clinician, I’ve seen how heavy cannabis use can be a factor in violence,” said coauthor and King’s College London professor Marta Di Forti in a statement. “We’ve been cautious for a long time about how far we could go in describing this link, but a review of this size lets us speak with more confidence about the risks, while being careful not to stigmatise people who use cannabis more broadly.”
“As cannabis becomes more commercialized and legalised around the world, the conversation about its risks has focused mostly on the person using it,” added coauthor and King’s College London professor of psychiatric research Sir Robin Murray. “This review shows that violence, both committing it and experiencing it, needs to be part of that conversation too.”
For their paper, the researchers examined 63 cannabis-related studies, involving just over 265,000 subjects.
The researchers found that cannabis users “may place themselves in risky situations,” which could help explain the “increased vulnerability” to violence. Users may also be exposed to “peers who engage in substance use or criminal activities.”
The risk of violence was also more pronounced among psychiatric patients. Previous resarch has found that people who already suffer from pre-existing mental conditions such as psychosis may experience “poorer clinical outcomes” through continued cannabis use.
“Given the higher rate of cannabis use among individuals with severe mental disorders compared to the general population, this group represents a particularly at-risk population in terms of violent behavior,” the paper reads.
The researchers offered some key takeaways from their findings. At the societal level, the researchers suggest that “violence should be considered alongside other established cannabis-related harms when developing prevention strategies, public education campaigns, and regulatory policies.”
At the clinical level, the research highlights the “necessity for mental health professionals to routinely assess cannabis use in individuals presenting with violent tendencies, particularly among those with severe mental illness.”
However, to get a better picture of how cannabis use relates to violence, future studies will need to “disentangle causal pathways” by diving into how, why, and when people use the drug in more detail. Other studies should also “examine whether reducing cannabis use through clinical or public health interventions leads to reductions in violent behavior,” the researchers conclude.
Each year, about this time, the Karolinska Institute and Royal Swedish Academy of Sciences — both in Stockholm, Sweden — announce three world-changing achievements. People who pioneered the work in these fields will receive the most coveted science awards on Earth: the Nobels.
The first of the 2026 prizes was awarded for finding a light switch for the brain. The second goes for developing a literally super-cool way to study elusive particles bombarding Earth from outside our solar system. And the last prize highlights the importance of being able to preferentially make certain “handed” molecules.
All three achievements opened up major new windows on — and opportunities in — biology, physics and chemistry.
Let’s start with the human brain. It hosts nearly 90 billion neurons. They talk amongst each other through some 100 trillion connections. This brain chatter allows our minds to learn, adapt and interact with the world around us.
The 2026 Nobel Prize in physiology or medicine went to Karl Deisseroth, Peter Hegemann and Georg Nagel for developing ways to control nerve cells with light. The technique, called optogenetics, opened new ways to study the brain by turning individual neurons on and off. #nobel#optogenetics#sciencenewsNikk Ogasa Getty Images/Alexander Pytskiy/JONATHAN NACKSTRAND/JOHN SAEKI,LAURENCE CHU/VALENTINA BRESCHI,JONATHAN WALTER,SYLVIE HUSSON,OLIVIER THIBAULT
To find out how, brain scientists needed a special tool. They long “dreamed” of something that might let them “turn specific neurons on or off with great precision,” notes Abdel El Manira. He spoke on Oct. 5, describing the prize for this tool.
The path to the prize started in an unlikely place: the “eye spot” of a single-celled green alga.
In the early 2000s, biophysicists in Germany discovered a unique protein in that alga’s “eye” spot. The two researchers were Peter Hegemann (who now works at Humboldt University in Berlin, Germany) and Georg Nagel (at the Julius-Maximilians-Universität Würzburg in Germany). The protein that caught their interest had a long name: channelrhodopsin (CHAA-nel-roh-DOP-sin).
When light hits it, the protein produces an electrical impulse. This triggered the alga to move. Later research would show light caused that protein to open like a pore. That let positively charged ions flow into the cell. They are what caused the electrical impulse.
Hegemann and Nagel “had just discovered the switch neuroscientists had long dreamed of,” says El Manira.
Building on the that work, Karl Deisseroth tried using that protein to see if it could turn on brain cells. A neuroscientist, he works at Stanford University in California.
He was part of a team that inserted the gene to make channelrhodopsin into rat nerve cells. These were growing in dishes in the lab. Shining light on the cells triggered an immediate reaction.
This team also put the gene into nerve cells within the brains of living mice. The researchers inserted optical fibers at the same spots, right through the rodents’ skulls. By shining blue light through the fibers, the researchers could now control the movements of the rodents’ whiskers.
Researchers later went on to test the links between other brain circuits and behaviors.
In short order, optogenetics “transformed neuroscience,” El Manira says. It offered a window on the workings of healthy brains, he says. It helped show how brain circuits can be disrupted, too, he adds. Those findings, he notes, could help researchers treat conditions such as blindness, depression and dementia.
In fact, we didn’t have to wait long for news in one of those areas. Just two days after this Nobel was announced, other researchers described a light therapy for retinitis pigmentosa (Reh-tih-NY-tis Pig-men-TOW-sah). This blinding disease slowly kills off light-sensing cells in the eye’s retina. Optogenetics, the new report showed, helped improve light sensitivity in seven of 10 treated people.
Neutrinos have no electric charge. They can pass through objects without interacting. In fact, billions of these ghostly particles pass through each of us every second.
Fusion reactions in our sun form most of them. But some had been thought to come from much farther away — in high-energy particle collisions too far off to observe.
Detecting such neutrinos from well beyond our solar system had long been a goal of scientists. Because neutrinos are not deflected by magnetic fields and rarely interact with matter, detecting their path could point back to their distant source. Scientists hoped to one day figure out where and how the universe accelerated these super-small particles to super-high energies.
In the 1980s, physicist Francis Halzen of the University of Wisconsin–Madison had an insight: The South Pole should be an ideal place to look for the flashes of light created by the rare events when neutrinos collide with atomic nuclei. Ice deep within the Antarctic ice sheet could make a large, dark, transparent stage for such a neutrino light show.
Francis Halzen has won the 2026 Nobel Prize in physics for his vision and scientific leadership of the IceCube Neutrino Observatory. IceCube gave us an entirely new way to see the universe. #nobelprize#physics#sciencenews Nikk Ogasa Getty Images/MARCO BERTORELLO/NSF/Martin Wolf & Sven Lidstrom, IceCube
In part, Halzen got this year’s physics Nobel “for his decisive contributions to [IceCube].” notes physicist Mark Pearce. But Halzen also won for “the discovery of high-energy neutrinos of astrophysical origin,” he adds. Pearce, who chairs the Nobel committee for physics, spoke during the Oct. 6 award announcement by the Royal Swedish Academy of Sciences.
IceCube had been a gamble. “Nobody knew whether a kilometer-field detector was actually large enough to discover neutrinos beyond our atmosphere from the universe,” Halzen said in a phone call during the announcement ceremony.
In fact, he noted, “It only took us two years to detect them.”
This year isn’t the first time a Nobel has gone for work on neutrinos. Two physicists received the prize in 2015 for demonstrating that neutrinos have mass.
In nature, the building blocks of life exhibit a striking pattern. Many can exist in two mirror-image structures, much like your right and left hand. Such molecules are said to be chiral (KY-rul). However, in nature, such chiral molecules overwhelmingly occur in just one form. Amino acids, for instance, are nearly always left-handed.
Known as homochirality, this dominance of one type of handedness had long puzzled scientists.
When chemists first attempted to make chiral molecules in the lab, they ended up with roughly 50-50 mixes of right- and left-handed molecules. Why?
“It is this puzzle that this year’s laureates have solved,” said Heiner Linke. He spoke during the Oct. 7 announcement of the chemistry prize by the Royal Swedish Academy of Sciences.
Two scientists will split this Nobel prize. Henri Kagan works at the Université Paris-Saclay in France. Kenso Soai works at Tokyo University of Science in Japan.
Henri Kagan and Kenso Soai won the 2026 Nobel Prize in chemistry for their work on controlling the production of mirror-image molecules. Their discoveries have helped pharmaceutical companies develop safer drugs. #nobel#chemistry#sciencenews Nikk Ogasa Getty Images/Evening Standard/Paul Fievez/Keystone/JONATHAN NACKSTRAND
The award winners’ research has greatly aided development of medicines. A lot of active drug molecules are chiral. But while one form may have a medicinal effect, its mirror-image form might have no effect — or worse, be harmful.
Consider thalidomide (Thuh-LID-oh-myde). Thousands of babies were born in the 1950s with severe birth defects. Their mothers had been prescribed thalidomide while they were pregnant to treat anxiety and nausea. Science would later show that the left-handed form of the drug was toxic. (Even taking the “safe,” right-handed form wouldn’t solve the problem. In the body, it could morph into the left-handed form.)
In 1986, Kagan’s team was the first to report chemical reactions that would lead to production techniques that helped solve the problem. These could make a far larger than normal share of left- or right-handed forms.
Several years later, Soai and his colleagues reported that they had figured out how to make a chiral catalyst that could, in turn, be used to form itself. That allowed his team to perform reactions that resulted in products made almost entirely of one “handed” form of a chiral molecule.
“This is not the final answer,” Soai said of this work. He had called in from Japan to the Nobel announcement ceremony. Speaking to future generations, Soai said, “the study of chirality should be more and more developed.”
The new Nobel scientists will each get a medal. The winners in each category will also split 12 million Swedish kroner (roughly $1.2 million).
For about a decade, the mainstream understanding has been that psychedelics cause chaos in the brain. Brain networks—the stable patterns of communication that handle vision, attention, or our sense of self, and more—loosen and start talking to each other all at once. EEG traces get noisier and more complex. “Think of the networks of the brain as highways,” says Devon Stoliker, a neuroscientist at Monash University. “Under psychedelics, these highways break down into many different directions.”
In a recent Nature study, Stoliker’s team designed an experiment to test whether these directions are truly chaotic and random. Researchers gathered 62 people who had never taken a psychedelic before, gave them 19 milligrams of psilocybin, a common psychedelic found in certain fungi, and scanned their brains. Then, they used AI to analyze the drugged and sober brain scans. What emerged was not exactly chaos.
An uninterrupted trip
Stoliker thinks chaos is not a satisfactory explanation for psychedelics’ effect on the brain. “It never really explained why an individual would have a meaningful experience, why they might have insight, why they might experience clarity, and why these might translate into positive psychological changes,” Stoliker says. To investigate if there are other explanations, he and his colleagues designed a study called PsiConnect.
Our sweets cravings may have set the stage for the human brain to become big and powerful. That’s the finding of a new study.
The brains of our upright-walking ancestors, some 4 million years ago, weighed only around 300 grams (11 ounces). That’s about equal to a medium apple. Today, the human brain averages 1,500 grams (3.3 pounds). That’s about equal to 1.5 liters of water. Much of this brain expansion took place before early humans mastered both fire and cooking. That’s a point that marked when they could start regularly dining on energy-dense starches.
Carbohydrates come in two main classes. Sugars tend to be relatively simple molecules. Starches tend to be bigger and more complex. A new analysis of existing data from human ancestors, as well as chimps, suggests that a large share of their energy probably came from sugary carbs, such as those in fruits and honey.
Until now, much of how diet affected human evolution has centered on meat. Around 2.5 million years ago, our early upright-walking ancestors began eating more meat — raw at first, then eventually cooked. Meat is rich in protein and fat. And that appeared to play a big role in fueling our ancestors’ ever-expanding brains.
But Jennie Brand-Miller thought there might be more to the story. A nutrition scientist at the University of Sydney, in Australia, she wondered how sugars might have affected the evolution of our brains.
Fruits were a major part of the early hominid diet and remained so going forward in evolutionary history.swkunst/iStock/Getty Images Plus
A 2017 study had shown that fruit-eating primates had bigger brains than leaf-eating ones. Eating fruit boosts demands on various thought processes, other researchers had suggested two decades earlier. Might this have kickstarted the evolution of big brains in humans?
Explains Brand-Miller, “You need to remember when various species of ripe fruit begin to ripen, then you need to remember where it is in the forest.” And, she adds, “Your memory is associated with a bigger brain.”
“All these things kept adding pieces to this lovely tapestry, this puzzle that said fruit-containing sugars must be important [in human evolution],” she says.
Brand-Miller is part of a team that has now calculated the dietary needs of chimps, humans and three early species of human ancestors. To do this, the researchers combined data from fossils, teeth, the species’ metabolism and the biology of bodily processes.
Clever foraging skills would have helped fuel their energy-sapping brains. These would have included hunting, cracking nuts, grinding seeds or extracting bone marrow. Later, once cooking became common, humans could have turned to starches (such as grains, beans and tubers). But a constant need for sugary foods appears to have been a key player in our evolution. And it didn’t disappear after a shift to foods high in proteins and fat, such as meats.
Meat and sugars? “I see them as parallel stories, not one replacing the other,” Brand-Miller now says. “Animal foods were clearly important. They’re very nutrient dense.”
A past focus on meat-eating may have missed some food trends that helped build the human brain, agrees Julie Lee-Thorp. She’s an archaeologist at the University of Oxford in England. She did not take part in the new study.
For a long period, evolutionary biologists saw meat as a major energy source that helped fuel the growth and complexity of the human brain. And it did. But a new surprise is that sugary carbs did, too, and they may have even kicked off the brain’s evolutionary growth.Igoravris/iStock/Getty Images Plus
Focusing on meat’s role may reflect a modern bias, she adds. “Meat is a high-status food today,” notes Lee-Thorp. “And that has perhaps been carried over into the way we think about the past.”
But Brian Wood largely dismisses that. The study of human evolution has not been obsessed with meat-eating, he says. A biological anthropologist, Wood works at the University of California, Los Angeles. A diverse range of foods fueled our evolution, he says. And they were made possible by our growing “ability to capture and harvest high-quality, difficult-to-acquire foods.” This included hunting, sure. But, he adds, foraging for fruit, honey, nuts and the underground parts of plants was also part of it.
The animals may help reveal the causes of brain disease in people and point the way to treatments. But researchers already are calling for new ethical guidelines.
Scientists have uncovered two surprising forces that help guide how the human brain forms before birth. Before birth, the human brain is shaped in large part by an unusual class of stem cells known as radial glia. These cells help determine which brain cells are produced, when they appear, and how the cerebral cortex, the [...]
Alzheimer’s may begin to unravel the brain when a small group of neurons switches on a receptor it was never meant to use, triggering damage that spreads from synapses to memories. Alzheimer’s disease is often defined by amyloid plaques and tau tangles, but those hallmarks are part of a much wider breakdown. Neurons become overactive, [...]
As far as completely pointless ways to kill time on your phone, this is certainly one of the weirdest on record.
Behold the all-new invention of so-called “dopamine sites” — digital domains where you can browse and hunt for deals on nonexistent wares and services. Clothes, food delivery, you name it: you can pretend-shop for it all.
You don’t actually buy anything, crucially. You’re just pretending to have money to buy the things you want. It’s window-shopping reimagined for the age of doomscrolling.
But it’s also a little more than that. These cleverly-built sites simulate the experience down to checking out and “tracking” your shipment or delivery, and their absurdly realistic rituals can help people become more conscious of their spending habits. Supposedly.
The trend, according to the New York Times, originated in South Korea this spring, when Park Seohyun, a 21-year-old mechanical engineering student in Seoul, created a fake food-delivery site called “Food Never Arrives.” (It’s now an app).
Originally intended as a joke, she says, it lets you not only order nonexistent food, but provides you an estimate of the money and calories you saved by skipping on the real thing.
In a wintry economic climate, it became an unexpected hit.
“People began sharing it online and discussing whether it actually helped them resist ordering food,” Park told the NYT.
A wave of imitators followed. This summer marked the launch of “FakeHaul,” a dopamine site built by a Microsoft engineer that convincingly imitates shopping on Temu. Two developers in India inspired by Park’s site, Purvansh Parmar and Anshul Sharma, created “Food Never Comes,” which simulates food deliveries but provides real recipes for the food you didn’t actually order. Parmar and Sharma told the newspaper that their site had more than 2.7 million views since launching in June.
Whether these dopamine sites provide anything more than fleeting, empty pleasures is something experts are more skeptical about. Ravi Dhar, director of the Yale Center for Customer Insights, told the NYT that the “element of looking forward brings a lot of the pleasure, and we often crash after an event or feel let down.” Lingguo Xu, a behavioral economist studying anticipatory utility, warned that the dopamine tricks could quickly get old. And by simulating consumption, you risk developing “stronger cravings.”
Some take the original idea beyond getting high on simulated shopping. Ko Seojin, another South Korean developer, created a website for taking virtual smoke breaks called Damta World. You click to start smoking an animated cigarette, which starts burning on screen. You can “whisper” disappearing messages to other smokers on break, while a counter keeps track of the number of cigarette butts that have been tossed on the office rooftop each day.
Ko told the NYT that 150,000 people visit each month, and she says that some users have become real-life friends after meeting on the website. Those friendships, we hope, are something that’ll last longer than any fake-shopping dopamine hit.
The US government has been sharing more information about UFOs. That's fueling excitement over the possibility of the president announcing that humans are not alone.
The US government has been sharing more information about UFOs. That's fueling excitement over the possibility of the president announcing that humans are not alone.
Login
