A widely available food-preservation chemical is emerging as a disturbing factor in rising UK suicide deaths, particularly among younger people and men. Researchers say the scale may be underestimated and are calling for urgent restrictions on access and harmful online information.

A surprising stress-related signal may help the brain repair itself after injury. Researchers found that myelin-producing precursor cells rapidly release the stress hormone CRH near damaged brain tissue, helping control how those cells mature and rebuild protective nerve insulation. The same system also influences brain development and the thickness of myelin later in life. The findings could offer new clues about how early-life stress contributes to psychiatric disorders.

Women who used estrogen-only hormone therapy later in life were less likely to develop dementia and showed fewer signs of Alzheimer’s disease in their brains, according to a large study of more than 21,000 participants. Hormone therapy use was linked to 39% lower odds of a dementia diagnosis and 35% lower odds of Alzheimer’s-related brain changes at autopsy, including amyloid plaques and tau tangles. Biomarker tests also suggested less amyloid buildup among hormone therapy users.

Frequent cannabis users may wake up with unusually high levels of the stress hormone cortisol, suggesting their daily stress rhythms could be disrupted. Researchers say the finding raises questions about whether using cannabis for stress relief might, over time, interfere with the very system that helps the body handle stress.

Teens who start using cannabis may experience slower growth in memory, attention, language, and processing speed. Their abilities often developed normally at first, then began leveling off while nonusers continued improving. THC appeared to be the most likely driver, especially for worsening memory.

New research challenges the decades-old idea that children experience an “adiposity rebound” when their BMI begins rising around age 6. Although BMI returns to earlier levels, a more reliable measure showed that body fat does not rebound at all. The increase appears to come from growing muscle and lean tissue as children prepare for later growth. Researchers say this normal process has been mistakenly treated as an obesity warning sign for 42 years.

A person’s sleeping brain may reveal warning signs of dementia long before memory problems begin. Researchers used machine learning to analyze EEG recordings from about 7,000 adults and found that an older-than-expected “brain age” was tied to a sharply higher dementia risk. Every additional 10 years of brain aging raised that risk by nearly 40%.

Even mild inflammation during pregnancy led mouse offspring to develop persistent brain overactivity, sensory sensitivity, repetitive behaviors, and increased seizure risk. Remarkably, one dose of rapamycin improved nearly all of these problems within about two hours. The benefits were temporary, but they suggest that adult brain circuits may remain far more adaptable than previously believed.

A massive genetic study has identified nine new genes linked to hyperemesis gravidarum, the most severe form of pregnancy sickness, bringing the total number of known risk genes to ten. The discoveries provide fresh insight into why some women experience debilitating nausea and vomiting during pregnancy while others do not. Several of the newly identified genes are involved in appetite, nausea, metabolism, and brain function, opening the door to more targeted treatments.

An unexpected study found that young non-smokers with healthier diets had higher rates of lung cancer, raising questions about whether pesticide exposure from conventionally grown produce could play a role. Researchers stress that the findings are preliminary and require further studies before any conclusions can be drawn.

Researchers found that every pregnancy rewires the brain in its own way, with a second pregnancy bringing a different pattern of changes than the first. The discoveries could lead to better ways to recognize and treat maternal mental health challenges, including peripartum depression.

Heavy marijuana smoking may raise the risk of lung cancer and several head and neck cancers, according to growing research, but many important questions remain unanswered. Scientists are still trying to determine how much marijuana use is enough to significantly increase cancer risk. Edibles have not been linked to lung cancer so far, while the long-term effects of vaping marijuana and secondhand marijuana smoke are still being investigated.

A new once-daily weight-loss pill called orforglipron delivered better weight loss and blood sugar improvements than the leading oral semaglutide in a major clinical trial. The tablet could offer a more convenient alternative to injectable drugs like Ozempic and Wegovy because it doesn't require refrigeration or special timing with meals. It's also cheaper to manufacture, which could expand access globally.

A large study found that pregnant women are exposed to dozens of common chemicals, many of which were associated with earlier births and lower birth weights. Researchers also discovered that some replacement chemicals may be just as concerning as the substances they were designed to replace.

Teens who use cannabis may face a substantially greater risk of developing serious mental health conditions, including psychotic and bipolar disorders, according to a study of more than 463,000 adolescents. Researchers found cannabis use often preceded these diagnoses by nearly two years, strengthening concerns about its long-term effects on developing brains.

Researchers have concluded that nicotine vapes are likely to cause lung and oral cancers, based on evidence ranging from human biomarkers to animal and laboratory studies. The findings challenge the idea that vaping is a harmless alternative to smoking and suggest health risks may be emerging much sooner than many expected.

Depression appears to change what children notice in the faces around them, but the effect depends on family history. Kids with a higher inherited risk became more focused on sadness, while lower-risk children lost some of their natural attention to happy expressions.

A child psychologist says grandparents are more important than ever as youth mental health challenges continue to rise. He argues that children need supportive relationships, meaningful conversations, and a sense of purpose—not just pressure to achieve. Grandparents can help by listening, encouraging, and creating positive experiences that strengthen emotional resilience.

A new treatment that blocks an aging-related protein restored lost cartilage in old mice and helped prevent arthritis after knee injuries. Human cartilage samples showed similar signs of regeneration, raising hopes for a future drug that could repair joints instead of replacing them.

A long-overlooked organ may hold surprising clues to healthy aging and cancer survival. Researchers at Mass General Brigham used AI to analyze CT scans from tens of thousands of adults and found that people with healthier thymuses—a small immune-system organ once thought to become largely irrelevant after childhood—lived longer and had substantially lower risks of heart disease, cancer, and death.