One in four strokes is called a lacunar stroke. It happens deep inside the brain when tiny blood vessels fail. It is one of the leading causes of disability, cognitive decline, and dementia.
For decades, doctors have treated it the same way they treat most other strokes: aspirin to prevent clotting, statins to reduce cholesterol. The assumption has been that fatty plaque is blocking the arteries that feed those tiny vessels.
A new study just followed 229 stroke patients with MRI scans for a year and found something that challenges that assumption entirely.
The patients who had lacunar strokes did not show the artery narrowing that the standard treatment targets. They showed something else.
There is something millions of people have noticed about themselves but cannot quite explain.
Difficult things feel harder to start than they used to. Not impossible. Just somehow more expensive. A book that would have held your attention for hours now loses you after a few pages. A task that requires sustained concentration keeps getting postponed. The effort feels larger than it should.
Researchers have been studying this for 20 years and producing inconsistent results. Some studies find screen time damages attention. Others find almost no effect. Nobody has been able to explain why both sets of results exist.
A new framework just published in Nature Human Behaviour says both sides have been asking the wrong question.
The problem is not that phones make you less capable of focusing. In a lab setting, with a defined task and no alternatives, heavy screen users perform just as well as anyone else.
The problem is what happens to the brain's internal accounting system after years of environments where reward is instant and effort is essentially zero.
Most people take vitamin C for their immune system. Almost nobody takes it thinking about what it might be doing to the structure of their brain.
Researchers in Japan just scanned the brains of more than 2,000 older adults and measured how much vitamin C was actually circulating in their blood. Not what they ate. What was in their blood. The pattern that emerged across all 2,000 of them was the same. The lower the vitamin C, the less gray matter. And the weaker the connections inside the brain network most closely tied to memory, attention, and the earliest warning signs of cognitive decline.
The brain, it turns out, concentrates vitamin C to more than twice the level found in the rest of the body. It appears to have a sustained, specific demand for it.
The study cannot yet say whether low vitamin C causes the brain changes or simply accompanies them. But the signal was consistent enough across 2,000 people that the researchers say it is no longer a question that can be set aside.
Parkinson’s disease has been studied in laboratories for decades, but almost everything researchers know about it has been learned through methods that cannot replicate how the disease actually begins in people. The standard approach involves injecting animals with powerful neurotoxins that rapidly destroy dopamine-producing brain cells, producing Parkinson’s-like symptoms within days. It is useful for studying what happens after the damage occurs. It tells researchers almost nothing about why the damage occurs in the first place, or what set the process in motion years before a person notices their first tremor.
A new study from Texas A&M University has changed that by proving something researchers have theorized for decades but never been able to demonstrate directly: a natural viral infection, one that does not require any toxic chemicals and does not require any genetic modification, can trigger the exact sequence of brain damage that defines Parkinson’s disease, and the damage continues long after the virus itself has been eliminated from the body.
There is a condition that affects hundreds of thousands of people worldwide, probably more.They spend hours each day lost in elaborate fantasy worlds they cannot stop entering. They pace or sway while they do it. They use music as a trigger. They lose time they needed for work, relationships, and basic obligations to a habit they did not choose and cannot explain. Psychiatry has a name for it: maladaptive daydreaming.
What psychiatry does not have is a diagnosis for it. It does not appear in the DSM. Clinicians typically redirect these patients toward ADHD, OCD, or depression, all of which may be present but none of which captures what the person is actually experiencing. So hundreds of thousands of people across the world have turned to internet forums instead.
A new meta-analysis just reviewed 40 studies covering 24,977 people and found something the clinical system cannot ignore much longer.
Professional tennis players can begin moving toward where a serve will land before the ball is even struck. Ask them afterward to describe exactly where it bounced inside the service box, and their memory is imprecise. But the rare serve that goes somewhere unexpected, the one down the middle when every previous serve went wide, they remember with the kind of spatial precision they cannot summon for the hundred serves that went exactly where they predicted. Neuroscientists have known for decades that this pattern exists. Why the brain trades memory quality for speed on familiar events, and floods attention into unexpected ones at the cost of reaction time, has been the subject of a 30-year unresolved debate. A new study from the University of Sydney has finally settled it, and what the researchers found reveals that the brain is not choosing between two strategies at all.
For decades, neuroscientists believed that attention was controlled primarily by the prefrontal cortex, the most evolved part of the human brain.
Then researchers at Johns Hopkins tried switching off a small cluster of ancient neurons in the brainstem of mice.
The animals became immediately unable to filter out distractions. Not because their vision failed. Not because they stopped caring. Because something deep in their brainstem, something that predates the mammalian cortex by hundreds of millions of years, had been turned off.
The behavior was identical to the defining symptom of ADHD.
The next day, they turned the neurons back on. Focus returned completely.
Birds have these neurons. Fish have these neurons. Every vertebrate alive appears to have them. And humans almost certainly do too.
If the researchers are right, the most fundamental mechanism of attention in the vertebrate brain is not located where anyone thought it was. And the drugs currently prescribed for ADHD may be targeting the wrong part of the brain entirely.
Scientists followed 502 children from infancy all the way to age 10 measuring their screen habits six different times and what they found overturns how most parents think about screen time.
It turns out that the total amount of screen time matters less than when that screen time happens. And the most dangerous window is not what most experts have been warning about.
Something is making younger generations age faster than their parents did at the same age. A study published today in Nature Medicine by Washington University researchers measured biological age using nine standard blood biomarkers across 154,169 people in the UK Biobank and found that people born after 1965 are biologically older at equivalent life stages than those born a decade or two earlier. That generational gap in biological aging was directly associated with higher early-onset cancer risk, independent of inherited genetic cancer risk, with a 42% higher risk of early-onset lung cancer, a 22% higher risk of gastrointestinal cancer, and a 36% higher risk of uterine cancer for each measurable unit of accelerated aging. The same nine biomarkers used to calculate this are already collected in a standard blood panel. The study doesn't identify what caused faster aging in younger generations, but it gives the clearest biological answer yet to why cancer rates in people under 50 keep rising.
Over 50% of California’s water is contaminated with toxic forever chemicals
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An alarming new analysis reveals that toxic 'forever chemicals' known as PFAS have contaminated roughly 50 percent of California’s tested surface water and sediment samples.
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Researchers point to the state's massive agricultural sector as a primary driver, revealing that California farms applied an average of 2.5 million pounds of PFAS-containing pesticides annually between 2018 and 2023. Because these synthetic compounds resist natural degradation, they accumulate indefinitely in soil, wildlife, and aquatic ecosystems, establishing a persistent environmental threat.
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The implications extend far beyond ecology, as long-term exposure to certain PFAS compounds is linked to increased risks of cancer, liver damage, and developmental issues. Compounding the concern is that the current study only evaluated a fraction of California's counties, meaning the actual contamination is likely far more widespread. As regulatory bodies face mounting pressure to address these persistent pollutants, these findings emphasize the critical need to reform agricultural practices before vital water resources are permanently compromised.
As people age, their muscles don't just get weaker, they may also stop doing something that's been quietly protecting them from cancer. A study published in Nature Communications by researchers at Duke-NUS Medical School found that healthy muscle releases tiny molecular packages into the bloodstream carrying a specific microRNA that actively suppresses tumor growth in other tissues. Aging muscle releases far fewer of these packages, and what it does release carries much less of the protective cargo. When researchers exposed colorectal, lung, and bile duct cancer cells to vesicles from young, healthy mouse muscle, the vesicles sharply reduced cancer cell growth. Vesicles from old muscle couldn't do the same. The pathway controlling this entire system, the researchers found, can be reactivated through exercise.
Ozempic and Wegovy are approved for weight loss and diabetes. A new study from Rutgers University, published this month in the journal Criminology, found a connection nobody set out to look for. Analyzing survey data from 821 adults who had used a GLP-1 medication, researchers found that among people who had stopped taking the drug, impulsivity and violent behavior tracked together the way decades of criminology research predicts: more impulsive people reported more violence. Among people currently taking the drug, that connection was about 62% weaker. The drug didn't make people less impulsive. It appeared to weaken the link between feeling an impulse and acting on it violently, something researchers compared to a brief chemical pause that mimics what cognitive behavioral therapy is designed to teach.
About 30 percent of the weight people lose on tirzepatide, sold as Zepbound and Mounjaro, isn't fat, it's muscle. A phase 2 trial published in Nature Medicine tested whether adding a second drug, apitegromab, could change that. In the trial, 102 people took tirzepatide plus either apitegromab or a placebo for 24 weeks. The apitegromab group lost the same amount of weight and the same amount of fat as the placebo group, but lost 54.9 percent less muscle, ending up with a weight loss that was roughly 85 percent fat instead of 70 percent fat. The drug wasn't built for weight loss. It was originally developed for a rare neuromuscular disease, and works by blocking a protein whose entire function is to limit how much muscle your body builds and keeps.
You don't have one biological age. You have dozens, one for nearly every tissue type in your body, and a new study from Stanford shows they can be wildly different from each other. Researchers analyzed over 7,000 blood proteins from more than 60,000 people and built models that estimate a separate biological age for more than 40 distinct cell types, from brain immune cells to lung tissue to musculoskeletal cells. About a quarter of people showed one specific organ system aging dramatically faster than the rest of their body, and that pattern predicted real outcomes: people with two copies of the Alzheimer's risk gene APOE4 whose brain support cells looked unusually old had triple the risk of developing the disease compared with APOE4 carriers whose same cells looked young, a difference invisible to a standard genetic test alone.
E-cigarettes have been marketed for over a decade as the safer way out of smoking, something millions of ex-smokers switched to specifically to protect their health. A study published this month in Nature Medicine followed more than 4.5 million adults with a smoking history in South Korea for up to a decade and found that people who quit cigarettes but kept vaping daily had a 56 percent higher risk of developing lung cancer, and a similarly elevated risk of dying from it, compared with people who quit smoking and didn't take up e-cigarettes. Current smokers still had the highest risk of all. But among people who'd already done the hard part, quitting cigarettes, the ones who replaced them with vaping ended up worse off than the ones who walked away from nicotine completely.
Researchers at Mount Sinai and Boston Children's Hospital sequenced 149 cancer-driving genes in brain immune cells from 190 Alzheimer's patients and 121 healthy older adults, and found that mutations in three genes, DNMT3A, ASXL1, and TET2, the same genes that drive certain blood cancers, showed clear signs of having been selected for specifically inside Alzheimer's brains. The same mutations turned up in patients' blood, suggesting these cells originated from blood-forming stem cells, crossed into the brain, and then expanded further once there. When the team recreated the mutations in lab-grown brain immune cells using CRISPR, the cells became more inflammatory and more proliferative, the same pattern linked to neurodegeneration in other studies. The same genes have shown protective associations with Alzheimer's in some earlier research, which the new findings don't resolve, but the mutations are detectable in a routine blood draw and drugs targeting them already exist from cancer treatment.
Cognitive decline with age has been treated as close to a law of nature: processing speed slows, memory becomes less reliable, and mental sharpness erodes gradually after early adulthood. A three-year study published in Scientific Reports by researchers at the University of Texas at Dallas tracked nearly 4,000 adults ranging from 19 to 94 years old and found something that does not fit that model. Brain health, measured across cognitive function, social connectedness and purpose, and emotional well-being, improved over the three-year period across the entire age range, including participants in their 80s and 90s. The gains came from just a few minutes a day of structured brain-training activity. Age did not determine whether someone improved. For nearly everyone in the study, including the oldest participants, the trajectory pointed up, not down.
Up to 40 percent of people with depression do not primarily feel sad. They feel nothing. Things that used to bring pleasure stop registering, motivation disappears, and current antidepressants, which mainly target serotonin, often do very little for this specific symptom called anhedonia. A randomized, double-blind, placebo-controlled trial published in Nature Medicine tested whether a drug used for Parkinson's disease could fill that gap. In 82 patients with treatment-resistant depression and significant anhedonia, adding the Parkinson's drug pramipexole to existing treatment produced significantly greater improvement than placebo, an effect that persisted for six months. Brain scans using ultra-high-resolution imaging showed exactly why: the drug measurably increased activity in the brain's reward system, the same system that goes quiet in anhedonia. For nearly half of all people with depression, the symptom that current treatments are least equipped to address may now have a specific answer.
For decades, research has shown that children from lower-income families tend to have measurably different brains than children from higher-income families, but nobody could explain the pathway connecting a family's financial circumstances to a child's developing nervous system. New study analyzed brain scans from nearly 12,000 children and tested 649 different variables from their lives, covering everything from parenting style to screen time to neighborhood wealth. Out of all 649, the strongest predictors of brain differences were overwhelmingly socioeconomic, 37 of the top 40 for brain function and 35 of the top 40 for brain structure. But the brain regions affected were not the ones researchers expected. The differences concentrated in areas controlling sensory processing and motor function, not memory or attention, and the explanation the researchers arrived at points to something every household can recognize: sleep, stress, and screen time.