Mind & body, in brief

US overdose deaths fell from about 111,000 a year at the peak in mid-2023 to under 71,000 a year by the end of 2025. [1]

One common explanation was naloxone, a medicine that reverses an opioid overdose within minutes, often given as a nose spray. [1][4]

A study in JAMA, a US medical journal, tested that idea on 21 October. [1]

Its authors, including Michael Barnett of Brown University, studied nearly 186 million ambulance and other emergency call-outs from May 2020 to December 2025. [1]

From May 2023, call-outs for opioid overdoses that people survived fell about 33% below the expected level. [1]

The number of times crews gave naloxone fell too, by about 21%. [1]

If naloxone were saving more people, survived overdoses would have gone up as deaths fell. Both went down, which points to fewer overdoses happening at all. [1]

The data cannot see a bystander who gave naloxone and never called 911, the US emergency number. [1]

Barnett says a break in the supply of fentanyl, a very strong illegal opioid, best explains how sudden and widespread the fall was. [1]

A paper in the journal Science in January said the shortage may have started in China. [2] Opioid deaths in Canada also fell 17% in 2024. [2]

The US overdose death rate fell 24.4% between 2023 and 2024, driven by fewer deaths involving fentanyl. [3]

Barnett warns that a fall caused by supply can reverse, and the decline already slowed in 2025. [1]

Why it matters. The next test is the 2026 death count: if it keeps falling after the slowdown in 2025, the fentanyl shortage is holding, and if it rises, suppliers have found new sources. [1]

The Danish researcher leading a US-funded hepatitis B vaccine trial in Guinea-Bissau, a small West African country, said on Wednesday it will not go ahead. [5] Frederik Schaltz-Buchholzer wrote that the team did not get the approval it needed from Guinea-Bissau's government. [5] The trial would have given 14,000 newborns the vaccine either at birth or six weeks later, to compare the two. [7] The WHO, the UN's health agency, called that unethical in February. [6] Guinea-Bissau's authorities took the team's vaccines in a search of its offices on Monday. [5]

Why it matters. The US Centers for Disease Control and Prevention had promised $1.6 million, and has not said whether that money will now go to vaccinating newborns. [5] Guinea-Bissau plans to give every baby the birth dose from 2028. [5]

The Trump administration is scoring states higher for part of its $50 billion Rural Health Transformation Program if they scrap or loosen certificate of need laws. [14] Those laws make a hospital prove a community needs it before it builds or expands. [14] More than 30 states have one, and six said in their applications they would revisit theirs. [14] Tennessee voted in April to undo most of its rules over four years. [14]

Why it matters. Defenders of the laws say big chains will build where patients pay best, and small rural hospitals will close or sell. [14] In Tennessee, HCA, the largest US hospital company, won approval for a hospital 20 minutes from a smaller rival. [14]

Georgia, a US state, will spend more than $12 million of its rural health money on obstetric carts for 43 rural hospitals that no longer deliver babies. [15] Each cart holds supplies for an emergency birth, such as tools to help a newborn breathe. [15] Only 36% of Georgia's rural hospitals still have a labour ward. [15] In Lavonia, Kara Holden drove about an hour to give birth on 11 October after her local unit closed. [15]

Why it matters. A maternal health worker told KFF Health News that emergency-room doctors may see a serious birth emergency only a few times a year. [15] One obstetrician called the carts a band-aid on a haemorrhage and wants money to keep wards open instead. [15]

About six in ten people in California's 22nd congressional district are on Medicaid, the US public health insurance for people on low incomes. [22] Their congressman, Republican David Valadao, voted for the 2025 law expected to cut Medicaid spending by more than $900 billion through 2034. [22] By 1 January 2027 at the latest, 44 states must make many adults on Medicaid show they work, train or volunteer to keep it. [24][22] Valadao faces Democrat Randy Villegas on 3 November. [22]

Why it matters. A left-leaning think tank estimates 60,000 more people in the district could be uninsured by 2034. [22] The US Congressional Budget Office expected the law's Medicaid changes to leave 7.5 million more people uninsured nationwide. [24]

The US Centers for Disease Control and Prevention will not renew its main HIV prevention grant to community groups, according to reports that KFF, a US health research group, sets out. [23] That grant paid $239.3 million to 96 groups from 2021, and nearly half went to the US South. [23] Money now goes through state and local health departments instead. [23] The first extra round, on 3 September, came to $91 million, 24% less than the $120 million announced. [23]

Why it matters. The groups ran HIV tests, linked people to care and helped them get PrEP, a pill that prevents HIV. [23] Tennessee has turned down CDC HIV prevention money, so its groups get nothing through the new route. [23]

Nearly 17% of autistic eight-year-olds in the US meet the criteria for profound autism, a new estimate from the US Centers for Disease Control and Prevention finds. [8] Its estimate in 2023 was 27%. [8] Profound autism describes autistic people who will need care around the clock as adults. [8] The new count uses a tighter definition that adds everyday living skills, and the total number of autistic children has also grown. [8] Only 54% of the 7,084 children had all the data the team needed. [8]

Why it matters. The rate ranged from 10% in Utah to 35% in Laredo, Texas, partly because places assess children differently. [8] A Boston doctor said 17% is still a big group of families who need intensive support. [8]

UK Prime Minister Andy Burnham said on Wednesday he supports making suicide prevention training compulsory for social workers in all of England's councils. [12] He was asked about Matilda Davis, a 36-year-old mother who cared full-time for her disabled son. [12] She took her own life in October 2025, minutes after a visit from social workers who had not had that training. [12] A coroner had already ordered her council, Warwickshire, to train 600 staff. [12]

Why it matters. Research from the University of Birmingham found 41% of parent-carers have thought about suicide. [12] In the UK and Ireland, anyone in crisis can reach Samaritans for free on 116 123. [12]

Twelve people with Parkinson's disease, a brain illness that slows movement, had less inflammation in their blood after two doses of psilocybin, a study in JAMA Psychiatry found on Wednesday. [9] Psilocybin is the drug in magic mushrooms. [9] The team at the University of California, San Francisco measured five inflammation signals, and the drop lasted a month. [9] The drug acts on a serotonin receptor that many body cells carry, not only brain cells. [9]

Why it matters. There was no comparison group and the patients knew they got the drug, so the authors say it must be repeated. [9] If it holds, the authors say it could matter for depression, anxiety and illnesses of the heart and metabolism too. [9]

Scientists sent tiny electric currents into the insula, a region deep inside the brain, in 87 people who already had electrodes in their brains for medical reasons. [10][11] Stimulating the back of the insula caused pain, heat or tingling in one part of the body. [10] The middle caused feelings inside the body, such as nausea or a full chest. [10] The front connects to thinking areas and sends signals to the rest of the insula. [11] The study appeared in Nature on Wednesday. [10]

Why it matters. A co-author at Stanford University said the insula does more than read the body: it partly shapes how a feeling is felt. [10] That pathway may help explain how thoughts change pain. [11]

Mice with a Parkinson's-like illness moved better after six weeks on two drugs, researchers report in PNAS, a US science journal. [17] One drug makes the blood release less oxygen into tissues, and the other stops the body making extra red blood cells to make up for it. [17] In 2025 the same team helped such mice by having them breathe air with 11% oxygen instead of the usual 21%. [17] In mice with Leigh syndrome, a rare illness that starves cells of energy, the pair lifted the middle lifespan from 62 to 158 days. [17]

Why it matters. The idea is that damaged brain cells cannot use all the oxygen they get, and the extra does harm. [17] All the work so far is in mice, and Vamsi Mootha of Harvard Medical School, one of the scientists, warns that low oxygen can be dangerous. [17]

The brain clears waste through fluid that flows along the outside of its blood vessels, a route called the glymphatic system. [16] In mice bred to model Alzheimer's disease, a team at the Korea Brain Research Institute found those channels narrower and the flow badly reduced. [16] Cholesterol built up in those brains, and the team suggests it may block the flow. [16] An outside expert called the work a starting point for ideas, not proof. [16]

Why it matters. Dementia affects around 50 million people worldwide, and Alzheimer's is its most common form. [16] The results come from slides of dead mice, so other scientists want the flow tracked in living animals. [16]

Pippa Boardman from Cornwall, in south-west England, learned she had breast cancer from a phone call by a hospital worker she barely knew. [13] He had looked at her medical records at the Royal Cornwall hospital in Truro, days before her consultant was due to give her the results. [13] Two days later, her consultant confirmed the cancer. [13] The hospital trust has apologised and says the worker could see her records for his job but should never have contacted her. [13]

Why it matters. The trust says it is reviewing its rules in line with stronger NHS England guidance on staff looking at patient records. [13] Boardman is recovering well and says she lost her privacy and dignity. [13]

Each day averaging 25C or more was linked to about 360 fewer births in France and 192 fewer in Italy, two new studies find. [18] The drop shows up nine to ten months after the heat, which points to fewer babies being conceived in hot weather. [18] Earlier studies in the US and Hungary saw some of the missing births made up later. [18] The French and Italian data show no such catch-up. [18]

Why it matters. Both countries already have falling birth rates, and births in France fell 22% between 2010 and 2025. [18] The authors say the link is real but small next to money worries and changing family plans. [18]

Researchers at Charite hospital in Berlin scanned the brains of 299 children aged 3 to 13, including 123 who had been maltreated. [19] They placed each child on growth charts built from the largest brain-scan database available. [19] On average the maltreated children sat lower on those charts, in both grey and white matter. [19] Lower placings went with lower intelligence scores and more behaviour problems. [19]

Why it matters. A link between how severe the maltreatment was and brain size did not hold up after statistical checks. [19] The study does not show whether the maltreatment caused the smaller brains. [19]

A survey of 4,300 university students in Egypt, Yemen, Iraq, Sudan, Jordan, Syria and Palestine found 71% had muscle or joint pain in the past year. [21] The neck and lower back hurt most often. [21] Students who sat for longer were more likely to have pain, and those who slept six to eight hours were less likely. [21] For many, the pain stopped them doing their usual activities. [21]

Why it matters. The authors call for active breaks and adjustable desks at universities. [21] The survey asked students once, so it shows links, not causes. [21]

A study of 10,145 Chinese teenagers aged 13 to 18 found that stronger ones did better on two thinking tests. [25] They answered faster on working memory, which means holding facts in mind while using them, and on switching between tasks. [25] Strength was measured by grip and a standing long jump. [25] Strength showed no clear link with stopping an automatic response. [25] The link with working memory was stronger in girls than in boys. [25]

Why it matters. The data come from one moment in time, so the authors say trials are needed before anyone knows if building strength helps thinking. [25]

Researchers asked 192 people who had lost a leg and use an artificial one about their dreams. [20] Most of those who remembered their dreams saw their body whole in them. [20] People who felt the artificial leg had become part of their own body were less likely to dream of an injured body. [20] The study appeared in Scientific Reports, a Nature journal. [20]

Why it matters. The authors read this as a sign that the brain has folded the artificial leg into its picture of the body. [20] Once that happens, the leg stops being a daily reminder of the loss. [20]

Meta, which owns Facebook and Instagram, faces a class action in Australia's Federal Court over claims that its apps' addictive design harmed children and teenagers. [26] MinterEllison, the law firm bringing it, filed for eight people who say they were harmed before they turned 18. [26] A court order on Monday keeps their names and the full claim secret. [26] Meta says it will defend itself firmly. [26]

Why it matters. Australia already banned social media for children under 16 in 2025. [26] In August, Meta agreed to settle claims from nearly all US states that it designed its apps to hook children. [26]

Chinese people who drank tea three or more times a week had an 11.2% lower risk of diseases of the blood vessels, a study of nearly 500,000 adults followed for nine years found. [27] The link was strongest for strokes caused by a blocked artery, at 36.6% lower. [27] Very hot tea went with a 16% higher risk instead. [27] The study appeared in the Journal of Internal Medicine. [27]

Why it matters. The study only watched what people did, so other parts of their diet and lifestyle may explain the gap. [27] A dietitian at the British Heart Foundation, a UK heart charity, said it does not prove a daily cup protects the heart. [27]

Hims, a US online clinic with 2.9 million customers, has started offering testosterone treatment to men after an at-home blood test. [28] The test uses a small device stuck on the arm, and a lab checks 21 markers in the blood, including testosterone. [28] Men must also have a video call with a clinician, because US law treats testosterone as a controlled drug. [28] Hims says men with no symptoms will not be treated, whatever their level. [28]

Why it matters. In 2022, researchers posing as patients found six of seven online clinics offered testosterone even with normal levels. [28] A US urologist warned that testosterone treatment can cause infertility. [28]

Abu Dhabi's health department has launched Project Cradle, a two-year study that gives women with high-risk pregnancies an Oura smart ring. [29] The ring records heart rate, sleep, temperature and activity from early pregnancy until birth. [29] Researchers will test whether these signals change in the weeks before a baby comes too early. [29] Corniche Hospital and Mediclinic Airport Road will take part. [29]

Why it matters. About one in ten babies worldwide is born before 37 weeks, which can leave lasting harm to breathing and development. [29] A clear warning sign would give doctors time to treat the baby's lungs and brain before birth, or move the mother to a specialist unit. [29]