Normally, it's easy to see that someone has broken an arm: the cast gives it away. Or that they have a cold: they don't stop sneezing and blowing their nose. And with a simple analysis, we can know if a person is hypertensive or diabetic. On the other hand, mental illnesses, which can be just as painful and disabling as physical ones, tend to go more unnoticed, often because they don't show visible signs and because they don't have quantifiable biomarkers. Despite everything, their impact is great: it is estimated that one in four adults has a mental health problem.

Although postpartum depression has been formally recognized since at least the 14th century, it wasn't until well into the 20th century that it was labeled and defined as we understand it today: a mood disorder, in some cases severe enough to threaten survival, that appears around the time of childbirth. It could affect, on average, 10-20% of women. In fact, it is estimated to be the most common mental illness worldwide and the second leading cause of disability. Furthermore, it has been shown to be independent of age, ethnicity, and socioeconomic and cultural factors. Despite being so common, its causes are still unknown, although it is assumed that hormonal changes related to pregnancy play a significant role, along with various social and emotional factors and the fatigue inherent in the situation. The illness likely has more complex roots, because we have recently seen that men can also suffer from this type of problem. In fact, postpartum depression in men could be almost as common as in women (around 10% on average, although in some countries it's closer to 20%), but it's still less studied and often goes unnoticed. This is understandable: mothers bear the full weight of pregnancy, which is why we've traditionally paid little attention to the mental health of fathers.

The effect of hormones on brain function is a controversial topic because it lends itself to abuse by those seeking scientific confirmation of their biases. We have often heard that women's brains are not as good as men's in processes requiring mathematical skills, for example. Sexist statements of this kind are easy oversimplifications of an extremely complex and interesting phenomenon, which slow down research in this field. Because what is evident is that all the body's tissues are subject to the strong biological influence of these powerful molecules called hormones. If there are significant differences in the physiology of the liver, heart, or immune system between men and women, to cite a few well-studied examples, it would be very strange if the brain were the only organ that escaped their influence. A few years ago, a study was conducted that demonstrated that in humans, the male brain cannot be macroscopically distinguished from the female brain. It stirred up quite a controversy because it seemed to disprove the importance of hormones. The thing is, functional differences aren't necessarily visible to the naked eye.

When we're sick, the doctor prescribes a pill, but we rarely think about how that drug got to us. The process begins with scientists studying a library of chemical compounds to choose the most suitable one to solve the problem while causing minimal side effects. To achieve this, they conduct an initial experiment on cells growing in a culture dish, then on animals, and finally on humans. This is the protocol that has been used for decades and has allowed us to have pharmacies full of solutions for almost every disease. But there have always been critical voices questioning whether animal experimentation was truly necessary. The reasons are primarily ethical, related to the unnecessary suffering of beings capable of feeling pain. Lately, this viewpoint has gained influence, and some countries have begun to take steps to eliminate these studies altogether.

A surprising article was published a few weeks ago in Nature This says a lot about how little we know about our brains. According to an analysis of blood markers in the general population of Norway, 25% of people over 85 have Alzheimer's. This figure was previously thought to be between 7% and 13%, so the study reveals that the disease is much more common than previously believed and often goes undetected. These data imply that the abnormal and accelerated aging of the brain that we associate with Alzheimer's may not be as rare as we would like to think, especially as life expectancy continues to increase—which in almost every country has been on an upward trend for over a century. That's why it's so important to find ways to delay the loss of brain function, which is typical of this disease. The decline in intellectual abilities that we see with age, both in healthy people and in those who will eventually develop dementia, depends mainly on two factors. The first is how quickly our brains age and degenerate, something we still can't accurately predict or measure. The second is what's called cognitive reserve, which is the intellectual capacity we've acquired over the years and which inevitably declines in the final stages of life. It could be compared to draining a bathtub: the time it takes to run dry depends on how quickly the water flows out (the first factor), but also on how full it was when we pulled the plug (the reserve we had).

In 1975, following a conference on recombinant DNA in Asilomar, California, a moratorium—self-imposed and widely accepted by experts—came into effect to allow time to assess the risks of the new technology, which for the first time allowed the mixing of genetic material from different species, thus creating modified organisms. The potential applications were fabulous, as was the possibility of generating unimaginable disasters. It was necessary to carefully consider the consequences of using the knowledge that had been acquired and to agree on minimum regulations that everyone could follow.

When we look back in a few years and assess the most significant technological and scientific advancement of the first quarter of the 21st century, it's quite possible that the winner will be the arrival of artificial intelligence in every home. From being a technology useful only in certain areas of science, it has evolved, with the emergence of LLCs (Extended Language Models) and generative artificial intelligence, into a tool that a large part of the population uses daily, sometimes even without realizing it.

All organisms made up of more than one cell, such as plants and animals, face a significant challenge: how to ensure their cells always act in a coordinated manner, prioritizing the common good. In biology, anarchy is dangerous, as demonstrated by one of the diseases with the greatest social impact even today: cancer. The disease begins precisely when the accumulated damage a cell has sustained forces it to behave selfishly and disorganized. It is not surprising, then, that evolution has found several ways to keep this threat under control, preventing organisms from dying of cancer before they have a chance to reproduce and ensuring the survival of their offspring.

It is well known that the proper functioning of our body depends on two types of factors: internal and external, or, in other words, genetics and environment. Most diseases are influenced, in varying percentages, by both components. Even the way we age depends as much on what we inherit as on what we do.

There are people who, when they wake up, aren't human until they've had at least a couple of cups of coffee. Others, on the other hand, wake up in a good mood and with their brains already working at cruising speed as soon as they put on their sneakers. Technically—and with a touch of humor—the former have been labeled as night owls already the seconds how a morning larks, in honor of night owls and early morning larks, respectively. As much as it annoys us, neither of them is to blame for preferring a specific distribution of their daily activity/sleep pattern, what is called chronotype: belonging to one group or another basically depends on the genes passed on to you by your parents.

Where do we come from? It's one of the most difficult questions humanity has ever asked. From the beginning, religion has proposed more or less fanciful solutions to this enigma. But since we invented the scientific method—the best tool we have for approaching reality—we have begun to better understand the true origin of life as we know it. We are far from a definitive answer, but we have now discovered several of the long and complicated processes that have led to the emergence of intelligent beings on this planet.

Let's imagine the case of a middle-aged person who, one day, while searching through their phone, comes across a selfie they took a year earlier. Horrified, they realize that this image doesn't correspond to the one they see every day in the mirror: they can now count more wrinkles and much more gray hair. How can it be, if a relatively short time has passed, that they seem to have aged so quickly? The explanation should be that their body has experienced a more acute decline than usual. Indeed, that's what an article published in the magazine Nature Aging He claimed that it happens to all of us at least twice in our lives.

Surely some friend has explained that they remember things that happened to them when they were barely one year old. Others may go further and talk about previous experiences, even from the first few days after birth. Science has long said that all of this is false: the consensus is that the human mind doesn't form memories until two or three years old (in some exceptional cases, it could be a little earlier). Any image prior to that date has surely been constructed from what other people have told us, but it can't come from our own experiences. Or can it? A new study, recently published in the journal Science, questions this dogma and proposes that the brain is prepared to memorize earlier than we thought.

If someone mentions "water bears" in a conversation, they're likely to encounter surprised expressions from their interlocutors, who are probably imagining some kind of gigantic amphibious mammal they didn't learn about in class. If, instead of the nom de guerre, they use the official one, the result may not be very different, because not many people are familiar with the existence of tardigrades, one of the truly amazing animals that inhabit the Earth, capable of surviving the most extreme conditions on the planet... and in outer space! A recent article published in the journal Science reveals the possible secret of this unusual resistance.

Legend has it that the first person to run a marathon, the Greek Pheidippides, died of exhaustion just minutes after completing the feat. It must be taken into account that the poor soldier did not expect that on that historic day in the 5th century BC, instead of ending up pierced by a Persian spear on the beach at Marathon, he would have to run tirelessly the 42.195 kilometers that separated the battlefield from Athens to announce victory over the invading troops.

Since February, Robert F. Kennedy Jr. is the Secretary of Health of the government of Donald Trump, the top public health official in the United States. It's terrible news for the entire planet. It's hard to predict which of the ideas Trump has implemented since returning to power will have the most profound negative impact on a global scale, but putting a conspiracy theorist anti-vaccine in charge of the health care of 340 million people has a good chance of winning the jackpot. The problem is that this prize will be paid in human lives.

Avatar It is a James Cameron film released in 2009 that surely everyone knows because it has the honor of being the highest grossing film in history. otakus You may know that this was the name of a cartoon series about a select few who can manipulate the four elements. Both franchises take their name from a Sanskrit word used in Hinduism to describe the earthly incarnation of a God or spirit, and which has become popular in the 21st century because it is commonly used to designate the representation of a user in the digital world. It is also this idea that has inspired the scientific meaning of the word. avatar to define any system that allows modeling what happens in an organism when it receives a treatment. Medical avatars come in many types, from digital to biological. The most recent, published in an article in Nature A few weeks ago, it is a mini-organ made from patient stem cells that can be used to predict whether or not a new treatment for rare genetic diseases will work.

When it comes to managing a pandemic well, you have to have as much information as possible to be able to take the right decisions. This knowledge is provided by science. But social urgency comes up against the fact that, by design, science is slow: it has to be very convinced before reaching any conclusions, to make sure it is correct. This difference in pace has created moments of tension since the emergence of covid-19, regarding, for instance, the issue of how the virus is transmitted: despite the months that have passed, no agreement has yet been reached, and this complicates defining the measures that are most effective in preventing contagion.