fbpx
Connect with us

The Conversation

Do hormonal contraceptives increase depression risk? A neuroscientist explains how they affect your mood, for better or worse

Published

on

theconversation.com – Natalie C. Tronson, Associate Professor of Psychology, of Michigan – 2024-06-24 07:20:05

Hormonal contraceptives have functions that go beyond just birth control.

Mindful Media/E+ via Getty Images

Natalie C. Tronson, University of Michigan

More than 85% of women – and more than 300 million people worldwide at any given time – use hormonal contraceptives for at least five years of their . Although primarily taken for birth control, many people also use hormonal contraceptives to manage a variety of symptoms related to menstruation, from cramps and acne to mood swings.

Advertisement

For up to 10% of women, however, hormone contraceptives can increase their risk of depression. Hormones, including estrogen and progesterone, are crucial for brain . So, how does modifying hormone levels with hormone contraceptives affect mental health?

I am a researcher studying the neuroscience of stress and emotion-related processes. I also study sex differences in vulnerability and resilience to mental health disorders. Understanding how hormone contraceptives affect mood can researchers predict who will experience positive or negative effects.

How do hormone contraceptives work?

In the U.S. and other western countries, the most common form of hormonal contraceptive is “the pill” – a combination of a synthetic estrogen and a synthetic progesterone, two hormones involved in regulation of the menstrual cycle, ovulation and pregnancy. Estrogen coordinates the timed release of other hormones, and progesterone maintains a pregnancy.

This may seem counterintuitive – why do naturally occurring hormones required for pregnancy also prevent pregnancy? And why does taking a hormone reduce the levels of that same hormone?

Advertisement

Line graph plotting rising estrogen levels peaking at day one of the menstrual cycle before decreasing, and progestorone levels peaking at day eight before dereasing

When estrogen and progesterone reach a certain threshold level, the body decreases their production.

Dharani Kalidasan/R.I. McLachlan et al. 1987 via Wikimedia Commons, CC BY-SA

Hormone cycles are tightly controlled by the hormones themselves. When progesterone levels increase, it activates processes in cells that shut off production of more progesterone. This is called a negative feedback loop.

Estrogen and progesterone from the pill, or other common forms of contraceptives such as implants or vaginal rings, cause the body to decrease production of those hormones, reducing them to levels observed outside the fertile window of the cycle. This disrupts the tightly orchestrated hormonal cycle required for ovulation, menstruation and pregnancy.

Brain effects of hormonal contraceptives

Hormonal contraceptives affect more than just the ovaries and uterus.

Advertisement

The brain, specifically an area called the hypothalamus, controls the synchronization of ovarian hormone levels. Although they're called “ovarian hormones,” estrogen and progesterone receptors are also present throughout the brain.

Estrogen and progesterone have broad effects on neurons and cellular processes that have nothing to do with reproduction. For example, estrogen plays a role in processes that control memory formation and protect the brain against . Progesterone helps regulate emotion.

By changing the levels of these hormones in the brain and the body, hormonal contraceptives may modulate mood – for better or for worse.

Hormonal contraceptives interact with stress

Estrogen and progesterone also regulate the stress response – the body's “fight-or-flight” reaction to physical or psychological challenges.

Advertisement

The main hormone involved in the stress response – cortisol in humans and corticosterone in rodents, both abbreviated to CORT – is primarily a metabolic hormone, meaning that increasing blood levels of these hormones during stressful conditions results in more energy mobilized from fat stores. The interplay between stress systems and reproductive hormones is a crucial link between mood and hormone contraceptives, as energy regulation is extremely important during pregnancy.

So what happens to someone's stress response when they're on hormonal contraceptives?

When exposed to a mild stressor – sticking an arm in cold , for example, or standing to give a public speech – women using hormone contraceptives show a smaller increase in CORT than people not on hormone contraceptives.

Stressed person looking at laptop with elbows leaning on surface and clasped hands over mouth

Chronic stress can worsen mood.

Vera Livchak/Moment via Getty Images

Advertisement

Researchers saw the same effect in rats and mice – when treated daily with a combination of hormones that mimic the pill, female rats and mice also show a suppression of the stress response.

Hormonal contraceptives and depression

Do hormonal contraceptives increase depression risk? The short answer is it varies from person to person. But for most people, probably not.

It's important to note that neither increased nor decreased stress responses are directly related to risk for or resilience against depression. But stress is closely related to mood, and chronic stress substantially increases risk for depression. By modifying stress responses, hormone contraceptives change the risk for depression after stress, leading to “protection” against depression for many people and “increased risk” for a minority of people. More than 9 out of 10 people who use hormonal contraceptives will not experience decreased mood or depression symptoms, and many will experience improved mood.

But researchers don't yet know who will experience increased risk. Genetic factors and previous stress exposures increase risk for depression, and it seems that similar factors contribute to mood changes related to hormone contraception.

Advertisement

Currently, hormone contraceptives are usually prescribed by trial and error – if one type causes side effects in a patient, another with a different dose, delivery method or formulation might be better. But the process of “try-and-see” is inefficient and frustrating, and many people give up instead of switching to a different option. Identifying the specific factors that increase depression risk and better communicating the benefits of hormone contraception beyond birth control can help make more informed decisions.The Conversation

Natalie C. Tronson, Associate Professor of Psychology, University of Michigan

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More

The post Do hormonal contraceptives increase depression risk? A neuroscientist explains how they affect your mood, for better or worse appeared first on .com

Advertisement

The Conversation

Federal funding for major science agencies is at a 25-year low

Published

on

theconversation.com – Chris Impey, University Distinguished Professor of Astronomy, University of Arizona – 2024-06-28 07:19:14
for science has traditionally been bipartisan, but fights over spending have affected research .
AP Photo/J. Scott Applewhite

Chris Impey, University of Arizona

Government funding for science is usually immune from political gridlock and polarization in . But, federal funding for science is slated to drop for 2025.

Science research dollars are considered to be discretionary, which means the funding has to be approved by Congress every year. But it's in a budget category with larger entitlement programs like Medicare and Social Security that are generally considered untouchable by politicians of both parties.

Federal investment in scientific research encompasses everything from large telescopes supported by the National Science Foundation to NASA satellites studying climate change, programs studying the use and governance of artificial intelligence at the National Institute of Standards and Technology, and research on Alzheimer's disease funded by the National Institutes of Health.

Advertisement

Studies show that increasing federal research spending benefits productivity and economic competitiveness.

I'm an astronomer and also a senior university administrator. As an administrator, I've been involved in lobbying for research funding as associate dean of the College of Science at the University of Arizona, and in encouraging government investment in astronomy as a vice president of the American Astronomical Society. I've seen the importance of this kind of funding as a researcher who has had federal grants for 30 years, and as a senior academic who helps my colleagues write grants to support their valuable work.

Bipartisan support

Federal funding for many programs is characterized by political polarization, meaning that partisanship and ideological divisions between the two main political parties can to gridlock. Science is usually a rare exception to this problem.

The public shows strong bipartisan support for federal investment in scientific research, and Congress has generally followed suit, passing bills in 2024 with bipartisan backing in April and June.

Advertisement

The House passed these bills, and after reconciliation with language from the Senate, they resulted in final bills to direct US$460 billion in government spending.

However, policy documents produced by Congress reveal a partisan split in how Democratic and Republican lawmakers reference scientific research.

Congressional committees for both sides are citing more scientific papers, but there is only a 5% overlap in the papers they cite. That means that the two parties are using different evidence to make their funding decisions, rather than working from a scientific consensus. Committees under Democratic control were almost twice as likely to cite technical papers as panels led by Republicans, and they were more likely to cite papers that other scientists considered important.

Ideally, all the best ideas for scientific research would receive federal funds. But limited support for scientific research in the United States means that for individual scientists, getting funding is a highly competitive process.

Advertisement

At the National Science Foundation, only 1 in 4 proposals are accepted. Success rates for funding through the National Institutes of Health are even lower, with 1 in 5 proposals getting accepted. This low success rate means that the agencies have to reject many proposals that are rated excellent by the merit review process.

Scientists are often reluctant to publicly advocate for their programs, in part because they feel disconnected from the policymaking and appropriations process. Their academic doesn't equip them to communicate effectively to legislators and policy experts.

Budgets are down

Research received steady funding for the past few decades, but this year Congress reduced appropriations for science at many top government agencies.

Advertisement

The National Science Foundation budget is down 8%, which led agency leaders to warn Congress that the country may lose its ability to attract and train a scientific workforce.

The cut to the NSF is particularly disappointing since Congress promised it an extra $81 over five years when the CHIPS and Science Act passed in 2022. A deal to limit government spending in exchange for suspending the debt ceiling made the 's goals hard to achieve.

NASA's science budget is down 6%, and the budget for the National Institutes of Health, whose research aims to prevent disease and improve public health, is down 1%. Only the Department of Energy's Office of Science got a bump, a modest 2%.

As a result, the major science agencies are nearing a 25-year low for their funding levels, as a share of U.S. gross domestic product.

Advertisement

Feeling the squeeze

Investment in research and development by the business sector is strongly increasing. In 1990, it was slightly higher than federal investment, but by 2020 it was nearly four times higher.

The distinction is important because business investment tends to focus on later stage and applied research, while federal funding goes to pure and exploratory research that can have enormous downstream benefits, such as for quantum computing and fusion power.

There are several causes of the science funding squeeze. Congressional intentions to increase funding levels, as with the CHIPS and Science Act, and the earlier COMPETES Act in 2007, have been derailed by fights over the debt limit and threats of government shutdowns.

The CHIPS act aimed to spur investment and job creation in semiconductor manufacturing, while the COMPETES Act aimed to increase U.S competitiveness in a wide range of high-tech industries such as exploration.

Advertisement
The CHIPS and Science act aims to stimulate semiconductor production in the U.S. and fund research.

The budget caps for fiscal years 2024 and 2025 remove any possibility for growth. The budget caps were designed to rein in federal spending, but they are a very blunt tool. Also, nondefense discretionary spending is only 15% of all federal spending. Discretionary spending is up for a vote every year, while mandatory spending is dictated by prior laws.

Entitlement programs like Medicare, and Social Security are mandatory forms of spending. Taken together, they are three times larger than the amount available for discretionary spending, so science has to fight over a small fraction of the overall budget pie.

Within that 15% slice, scientific research competes with K-12 education, ' health care, public health, initiatives for small businesses, and more.

Global competition

While government science funding in the U.S. is stagnant, America's main scientific rivals are rising fast.

Advertisement

Federal R&D funding as a percentage of GDP has dropped from 1.2% in 1987 to 1% in 2010 to under 0.8% currently. The United States is still the world's biggest spender on research and development, but in terms of government R&D as a fraction of GDP, the United States ranked 12th in 2021, behind South Korea and a set of European countries. In terms of science researchers as a portion of the labor force, the United States ranks 10th.

Meanwhile, America's main geopolitical rival is rising fast. China has eclipsed the United States in high-impact papers published, and China now spends more than the United States on university and government research.

If the U.S. wants to keep its status as the world leader in scientific research, it'll need to redouble its commitment to science by appropriately funding research.The Conversation

Chris Impey, University Distinguished Professor of Astronomy, University of Arizona

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Advertisement

Read More

The post Federal funding for major science agencies is at a 25-year low appeared first on theconversation.com

Continue Reading

The Conversation

AI companies train language models on YouTube’s archive − making family-and-friends videos a privacy risk

Published

on

theconversation.com – Ryan McGrady, Senior Researcher, Initiative for Digital Public , UMass Amherst – 2024-06-27 07:23:53
Your kid's silly could be fodder for ChatGPT.
Halfpoint/iStock via Getty Images

Ryan McGrady, UMass Amherst and Ethan Zuckerman, UMass Amherst

The promised artificial intelligence revolution requires data. Lots and lots of data. OpenAI and Google have begun using YouTube videos to train their text-based AI models. But what does the YouTube archive actually include?

Our team of digital media researchers at the of Amherst collected and analyzed random samples of YouTube videos to learn more about that archive. We published an 85-page paper about that dataset and set up a website called TubeStats for researchers and journalists who need basic information about YouTube.

Now, we're taking a closer look at some of our more surprising findings to better understand how these obscure videos might become part of powerful AI systems. We've found that many YouTube videos are meant for personal use or for small groups of people, and a significant proportion were created by children who appear to be under 13.

Advertisement

Bulk of the YouTube iceberg

Most people's experience of YouTube is algorithmically curated: Up to 70% of the videos users watch are recommended by the site's algorithms. Recommended videos are typically popular content such as influencer stunts, news clips, explainer videos, travel vlogs and video game reviews, while content that is not recommended languishes in obscurity.

Some YouTube content emulates popular creators or fits into established genres, but much of it is personal: celebrations, selfies set to music, homework assignments, video game clips without context and kids dancing. The obscure side of YouTube – the vast majority of the estimated 14.8 billion videos created and uploaded to the platform – is poorly understood.

Illuminating this aspect of YouTube – and social generally – is difficult because big tech companies have become increasingly hostile to researchers.

We've found that many videos on YouTube were never meant to be shared widely. We documented thousands of short, personal videos that have few views but high engagement – likes and comments – implying a small but highly engaged audience. These were clearly meant for a small audience of friends and family. Such social uses of YouTube contrast with videos that try to maximize their audience, suggesting another way to use YouTube: as a video-centered social network for small groups.

Advertisement

Other videos seem intended for a different kind of small, fixed audience: recorded classes from pandemic-era virtual instruction, school board meetings and work meetings. While not what most people think of as social uses, they likewise imply that their creators have a different expectation about the audience for the videos than creators of the kind of content people see in their recommendations.

Fuel for the AI machine

It was with this broader understanding that we read The New York Times exposé on how OpenAI and Google turned to YouTube in a race to find new troves of data to train their large language models. An archive of YouTube transcripts makes an extraordinary dataset for text-based models.

There is also speculation, fueled in part by an evasive answer from OpenAI's chief technology officer Mira Murati, that the videos themselves could be used to train AI text-to-video models such as OpenAI's Sora.

Advertisement

The New York Times story raised concerns about YouTube's terms of service and, of course, the copyright issues that pervade much of the debate about AI. But there's another problem: How could anyone know what an archive of more than 14 videos, uploaded by people all over the world, actually contains? It's not entirely clear that Google knows or even could know if it wanted to.

Kids as content creators

We were surprised to find an unsettling number of videos featuring kids or apparently created by them. YouTube requires uploaders to be at least 13 years old, but we frequently saw children who appeared to be much younger than that, typically dancing, singing or playing video games.

In our preliminary research, our coders determined nearly a fifth of random videos with at least one person's face visible likely included someone under 13. We didn't take into account videos that were clearly shot with the consent of a parent or guardian.

Our current sample size of 250 is relatively small – we are working on coding a much larger sample – but the findings thus far are consistent with what we've seen in the past. We're not aiming to scold Google. Age validation on the internet is infamously difficult and fraught, and we have no way of determining whether these videos were uploaded with the consent of a parent or guardian. But we want to underscore what is being ingested by these large companies' AI models.

Advertisement

Small reach, big influence

It's tempting to assume OpenAI is using highly produced influencer videos or TV newscasts posted to the platform to train its models, but previous research on large language model data shows that the most popular content is not always the most influential in training AI models. A virtually unwatched conversation between three friends could have much more linguistic value in training a chatbot language model than a music video with millions of views.

Unfortunately, OpenAI and other AI companies are quite opaque about their training materials: They don't specify what goes in and what doesn't. Most of the time, researchers can infer problems with training data through biases in AI systems' output. But when we do get a glimpse at training data, there's often cause for concern. For example, Human Rights Watch released a report on June 10, 2024, that showed that a popular training dataset includes many photos of identifiable kids.

The history of big tech self-regulation is filled with moving goal posts. OpenAI in particular is notorious for asking for forgiveness rather than permission and has increasing criticism for putting profit over safety.

Concerns over the use of user-generated content for training AI models typically center on intellectual property, but there are also privacy issues. YouTube is a vast, unwieldy archive, impossible to fully review.

Advertisement

Models trained on a subset of professionally produced videos could conceivably be an AI company's first training corpus. But without strong policies in place, any company that ingests more than the popular tip of the iceberg is likely content that violates the Federal Trade Commission's Children's Online Privacy Protection Rule, which prevents companies from collecting data from children under 13 without notice.

With last year's executive order on AI and at least one promising proposal on the table for comprehensive privacy legislation, there are signs that legal protections for user data in the U.S. might become more robust.

When the Wall Street Journal's Joanna Stern asked OpenAI CTO Mira Murati whether OpenAI trained its text-to-video generator Sora on YouTube videos, she said she wasn't sure.

Have you unwittingly helped train ChatGPT?

The intentions of a YouTube uploader simply aren't as consistent or predictable as those of someone publishing a book, writing an article for a magazine or displaying a painting in a gallery. But even if YouTube's algorithm ignores your upload and it never gets more than a couple of views, it may be used to train models like ChatGPT and Gemini.

As far as AI is concerned, your family reunion video may be just as important as those uploaded by influencer giant Mr. Beast or CNN.The Conversation

Ryan McGrady, Senior Researcher, Initiative for Digital Public Infrastructure, UMass Amherst and Ethan Zuckerman, Associate Professor of Public Policy, Communication, and Information, UMass Amherst

Advertisement

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More

The post AI companies train language models on YouTube's archive − making family-and-friends videos a privacy risk appeared first on theconversation.com

Advertisement
Continue Reading

The Conversation

Lucy, discovered 50 years ago in Ethiopia, stood just 3.5 feet tall − but she still towers over our understanding of human origins

Published

on

theconversation.com – Denise Su, Associate Professor of Human Evolution and Social Change, Arizona – 2024-06-27 07:23:34
The reconstructed skeleton of Lucy, found in Hadar, Ethiopia, in 1974, and Grace Latimer, then age 4, daughter of a research team member.
James St. John/Flickr, CC BY

Denise Su, Arizona State University

In 1974, on a survey in Hadar in the remote badlands of Ethiopia, U.S. paleoanthropologist Donald Johanson and graduate student Tom Gray found a piece of an elbow joint jutting from the dirt in a gully. It proved to be the first of 47 bones of a single individual – an early human ancestor whom Johanson nicknamed “Lucy.” Her discovery would overturn what scientists thought they knew about the evolution of our own lineage.

Lucy was a member of the species Australopithecus afarensis, an extinct hominin – a group that includes humans and our fossil relatives. Australopithecus afarensis lived from 3.8 million years ago to 2.9 million years ago, in the region that is now Ethiopia, Kenya and Tanzania. Dated to 3.2 million years ago, Lucy was the oldest and most complete human ancestor ever found at the time of her discovery.

Two features set humans apart from all other primates: big brains and standing and walking on two legs instead of four. Prior to Lucy's discovery, scientists thought that our large brains must have evolved first, because all known human fossils at the time already had large brains. But Lucy stood on two feet and had a small brain, not much larger than that of a chimpanzee.

Advertisement

This was immediately clear when scientists reconstructed her skeleton in Cleveland, Ohio. A photographer took a picture of 4-year-old Grace Latimer – who was visiting her father, Bruce Latimer, a member of the research team – standing next to Lucy. The two were roughly the same size, providing a simple illustration of Lucy's small stature and brain. And Lucy was not a young child: Based on her teeth and bones, scientists estimated that she was fully adult when she died.

The also demonstrated how human Lucy was – especially her posture. Along with the 1978 discovery in Tanzania of fossilized footprint trails 3.6 million years old, made by members of her species, Lucy proved unequivocally that standing and walking upright was the first step in becoming human. In fact, large brains did not show up in our lineage until well over 1 million years after Lucy lived.

A human spine and pelvis, with brown fossilized bones and modern white replacements.
Part of Lucy's reconstructed skeleton, on display at the Cleveland of Natural History in 2006.
James St. John/Flickr, CC BY

Lucy's bones show adaptations that allow for upright posture and bipedal locomotion. In particular, her femur, or upper leg bone, is angled; her spine is S-curved; and her pelvis, or hip bone, is short and bowl-shaped.

These features can also be found in modern human skeletons. They allow us, as they enabled Lucy, to stand, walk and on two legs without falling over – even when balanced on one in mid-stride.

In the 50 years since Lucy's discovery, her impact on scientists' understanding of human origins has been immeasurable. She has inspired paleoanthropologists to survey unexplored , pose new hypotheses and develop and use novel techniques and methodologies.

Advertisement

Even as new fossils are discovered, Lucy remains central to modern research on human origins. As an anthropologist and paleoecologist, I know that she is still the reference point for understanding the anatomy of early human ancestors and the evolution of our own bodies. Knowledge of the human fossil record and the evolution of our lineage have exponentially increased, building on the foundation of Lucy's discovery.The Conversation

Denise Su, Associate Professor of Human Evolution and Social Change, Arizona State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Read More

The post Lucy, discovered 50 years ago in Ethiopia, stood just 3.5 feet tall − but she still towers over our understanding of human origins appeared first on .com

Advertisement
Continue Reading

News from the South

Trending