Scientists

Single and repeated intravenous ketamine infusions are effective in reducing suicidal and depressive symptoms in patients with an acute episode of major depression. These are the main conclusions of a systematic review and meta-analysis published today in the journal JAMA Psychiatry, which also notes that long-term outcomes are not well established.

The Ministry of Health has announced that Spain will receive the MV Hondius in the Canary Islands “in accordance with international law and the spirit of humanitarianism”. The government is thus responding to a request from the World Health Organisation (WHO) and the European Union for the cruise ship, which is travelling from Argentina and has an outbreak of hantavirus on board, to dock in the Canary Islands, in the port of Granadilla, Tenerife. The European Centre for Disease Prevention and Control has assessed which passengers should be evacuated from the ship to Cape Verde, where it is currently located, and which will continue on to the Canary Islands. Once there, they will be examined and transferred to their home countries in accordance with safety protocols. The cruise ship is expected to arrive in the archipelago in three or four days.

The hallucinogen psilocybin, found in certain mushrooms, is being investigated as a treatment for conditions such as depression. A study published in Nature Communications shows that a single 25 mg dose of the compound can produce brain changes lasting up to a month after administration. These were measured using neuroimaging techniques in 28 healthy adults who had never taken psychedelics. In terms of psychological effects, participants showed increased cognitive flexibility, psychological insight, and well-being after one month.

The Ministry of Health has announced on social media that, depending on the epidemiological data gathered from the ship regarding a possible hantavirus outbreak during its stopover in Cape Verde, “a decision will be made as to which port of call is most appropriate”. Various reports suggest that the World Health Organisation (WHO) would have preferred the cruise ship to stop in the Canary Islands. “Until then, the Ministry of Health will not take any decision, as we have made clear to the World Health Organisation,” it stated. Furthermore, the Ministry of Health has indicated that, following a meeting with the WHO, a team of epidemiologists will inspect the vessel this afternoon to assess the condition of those on board, determine whether there are any further cases with symptoms, and identify high-risk and low-risk contacts. “This will aid decisions regarding repatriation procedures and the ship’s route.”

The geomagnetic field protects Earth from harmful cosmic radiation. Over the past two centuries, this field has weakened, coinciding with the growth of the South Atlantic Anomaly—a region of reduced magnetic intensity spanning South America and the South Atlantic Ocean—which poses risks to satellites and space missions. Research led by a Spanish team shows that this anomaly is a recurring event on timescales ranging from centuries to millennia, according to a reconstruction of the geomagnetic field over the past 2,000 years. The study, published in PNAS, shows that the current anomaly emerged after the year 1100 in the Indian Ocean and crossed Africa before reaching South America.

Colored microplastics and nanoplastics suspended in the atmosphere could contribute to global warming at a level equivalent to 16% of that caused by soot. The findings, published today in the journal Nature Climate Change, suggest that these particles may be previously unrecognized contributors to climate change, and that their role should be taken into account in future climate assessments. The authors note that laboratory experiments are a simplified version of atmospheric processes and that the global distribution of microplastic and nanoplastic particles must be determined more precisely through observations.

The World Health Organization (WHO) has reported a public health event involving a cruise ship sailing in the Atlantic Ocean that departed from Argentina. To date, two cases of hantavirus infection—generally acquired through exposure to the urine or feces of infected rodents—have been laboratory-confirmed, and there are five additional suspected cases. Of these seven individuals, three have died, and one is currently in intensive care in South Africa. “The risk to the general population remains low. There is no reason to panic or impose travel restrictions,” said Hans Henri P. Kluge, WHO Regional Director for Europe.

A Danish clinical trial involving 108 adults with obesity who were seeking treatment for alcohol use found that a weekly injection of semaglutide reduced the number of heavy drinking days. This decrease averaged about 12 days—50% greater than the eight-day reduction observed in the placebo group. The study is published in The Lancet and was funded by the Novo Nordisk Foundation, the company that develops these drugs.

Given current vaccination and cervical cancer screening campaigns, high-income countries could eliminate this disease by around 2048, according to a study published in The Lancet. However, the incidence of this cancer in low- and middle-income countries would decline by only 23% over this period if current trends continue, the article states. Elimination is defined as an incidence of fewer than four cases per 100,000 women.

A review published in The Lancet Psychiatry has examined the prevalence of major depressive disorder during pregnancy, the peripartum period—immediately before and after childbirth—and the postpartum period—up to twelve months after childbirth. The study, which used data from more than two million women and girls aged 10 to 59 from all regions of the world, showed that approximately one in 15 (6.8%) is affected by major depression during the year following childbirth and that the prevalence was highest during the first two weeks after childbirth (8.3%). The authors call for greater integration of screening, prevention, and treatment of this disorder during the peripartum period into current care models.