Science Friday - COP28 Climate Conference Ends | Why Are Some People Affected By Seasonal Affective Disorder?

Episode Date: December 15, 2023

Climate Conference Ends, With Few Immediate ResultsThe United Nations climate conference, COP28, ended this week in Dubai. After a lot of arguing over wording, the final agreement from the meeting calls for “transitioning away from fossil fuels in energy systems, in a just, orderly and equitable manner, accelerating action in this critical decade, so as to achieve net zero by 2050 in keeping with the science.” That text is significant in that it is the first time, surprisingly, that fossil fuel use was mentioned by name in a COP agreement. However, many critics of the proceedings point out that even this recognition is too little, too late, with few practical  routes to keep global warming under thresholds considered to be catastrophic.Casey Crownhart, climate reporter at MIT Technology Review, joins Ira to walk through the results of COP28. They also discuss other stories from the week in science, including research into morning sickness, clusters of brain cells that appear to do speech recognition tasks, a first look at asteroid samples from the OSIRIS-REx mission, and the tale of an unusual frog that camouflages itself as poop.Why Are Some People Affected By Seasonal Affective Disorder?As the shortest day of the year approaches, many people might notice their energy levels starting to dip. For some, winter is an especially challenging season. About 5% of adults in the United States experience seasonal affective disorder, also known as SAD. Ira talks with Dr. Kathryn Roecklein, associate professor of psychology at the University of Pittsburgh, about her research into what makes some people more susceptible to seasonal depression than others, and the most effective treatment options. Transcripts for each segment will be available the week after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

So many of us dread the winter months, but why do some people develop seasonal depression while others don't? So the theory is that some individuals are just more sensitive to those lower light levels. It's Friday, December 15th, and we made it. Today is Science Friday. I'm sci-fire producer Shoshana Bucksbaum. I can't stand when the days get shorter and shorter. But for some people, winter can be a serious mental health challenge, triggering seasonal effective disorder. or sad. In a bit, Ira talks with a psychologist who's working to better understand why some people are more susceptible to seasonal depression than others. But first, a roundup of the top science news of the week. The United Nations Climate Conference, known as COP28, ended this week in Dubai,

and after a lot of arguing over wording, not everyone came away happy. Joining me now to talk about the conference and other stories from The Week in Science is Casey Crownheart, climate reporter at MIT Technology Review. Welcome back, Casey. Thanks so much for having me back, Ira. So what's the good news and bad news about the COP 28? Yeah, definitely a mixed bag from this year's conference. There were some really kind of exciting pledges. You know, a lot of countries signed on to triple renewable energy by 2030 and reduce methane emissions.

That's a really powerful greenhouse gas. But like you said, not everybody came away happy. a lot of the fights kind of centered around how to talk about fossil fuels and what role fossil fuels should play in the future. This was the first cop that ever mentioned fossil fuels by name and the agreement. But the final kind of text was a little bit wishy-washy. Yeah, I heard all week about people praising the agreement, hey, we got fossil fuels in it, but as you say, nothing really concrete. Yeah, the bar is on the floor a little bit with these. It's tough because these conferences everybody has to agree on the final text. So you can imagine that it's a little bit tough to kind of get really strong wording in there.

So originally, you know, a lot of countries wanted it to say something like we want to phase out fossil fuels or at least phase down fossil fuels. But the final language kind of had some loopholes and caveats. So there's always next year, I guess. Well, is it a conference worthwhile at all then, Casey? If not much actually gets done. I mean, I think it is a necessary process. For me, I like to look at this as, kind of a temperature check of where the world is on climate change, you know, how everybody's thinking about it and kind of what commitments people are willing to make. But yeah, these agreements aren't going to be what actually pushes the needle forward on climate action, if you ask me. Yeah, there was a lot of attention given to the loss and damage fund, which ended up being

$700 million or to put it in perspective, the price of a contract for a pitcher for the Dodger. Yeah, so like you said, this is really, really important funding. So the loss and damage fund is basically giving money to more vulnerable countries to help them pay for all of those impacts of climate change. But yeah, we're really, really far from how much money is actually needed. So it's great to see that fund starting to get money put into it. But like you said, it's not very much. Let's move on to something where real progress was made. And I'm thinking of last week the FDA giving the green light to a treatment for sickle,

cell disease, very significant, is it not? Yeah, this is really great to see. And this was actually the first CRISPR treatment that's been approved by the FDA. So it's really exciting to see that technology kind of starting to have impacts for patients. And how soon might patients be getting this treatment? It could take a while. And this is also something, it's a really hard treatment to give to patients. So it takes months. But, you know, we could see this start to roll out before too long. Yeah, it's a really good story. We're going to be covering it in greater detail in the weeks ahead. Let's move on a bit to other health news. There's new research into severe morning sickness during pregnancy. Now, this is not your common everyday morning sickness, is it? Yeah. So a very common pregnancy symptom is vomiting and being sensitive to strong smells, but a small percentage of people who are pregnant about 2% experience severe symptoms, severe sickness, you know, vomiting multiple times a day. And now we're a little, little bit closer to understanding, you know, why some people get those symptoms. And what did the researchers find? Basically, there's this hormone that circulates in everybody's

blood, but for some people who are pregnant, they get really elevated levels of this hormone. It's called GDF 15. It's produced by the fetus. And if you don't usually have a high level of this hormone, and then you suddenly have a lot of it, that can be a cause of severe morning sickness. What can we do with that? I mean, I try to find some sort of. sort of remedy for it? Yeah. So I think because they realized that it also had to do with sensitivity, there's a potential that you could, for example, maybe give people if they're at a high risk for this, you could potentially give people a dose of this hormone before pregnancy to help kind of lower their sensitivity to it. So there definitely is kind of potential paths forward for therapies from

this research. All right. Let's move on to something a little more science fictiony. And I'm talking about clusters of cells in a petri dish that can apparently do some kind of voice recognition. Is that right? Yeah, this story was very trippy. One of our reporters at Tech Review covered it for us. So these researchers took clumps of human brain cells in the lab and they basically were trying to make them do computational tasks. So they sent electrical signals to these cells and then kind of watched what electro and electrochemical signals, the cells gave back in response. And basically they found that by giving them electrical signals that were tied to certain sounds, the cells seem to be able to kind of give the same response when they were given the same sound. So it's like very primitive

speech recognition, which is kind of wild. Yeah. So you're saying it's not actually hearing a sound. It's getting some signals. What is hearing? But yes, it's like getting electrical signals. I mean, our brain also gets electrical signals that our ear kind of decodes, I guess, in a way. So I don't know. This is all, it really broke my brain, this whole story, honestly. All right.

Well, let's move on to something that, well, Science Friday is nothing if we don't have a little space news each week, right? And a few months ago, the Osiris Rex mission brought back to Earth samples from an asteroid. And you're telling me now that the first results are in. Yes. So there's a big conference going on right now in California. The AGU conference and researchers at that conference are giving their first look into this data. We don't know everything yet. There's a lot, a lot of tests that the researchers want to do with this material.

But they say that, you know, there's a lot of carbon-based organic molecules in these samples that they got from the asteroid, which is really exciting. You know, they're saying that that might mean that these asteroids might give us some sort insight into the origin of life, which is really cool. Yeah, because carbon is very big in our life system, isn't it? Pretty central, pretty crucial. So yeah, the scientists will be looking for things like lipids and sugars and things that look kind of like DNA to kind of, you know, dig in a little bit more to see what these samples really are. Any idea when that will come back? We get more information on this stuff? We should hear a little bit more sometime in the new year. So within a few months,

we should have a little bit more information. But all the scientists say that, all these samples are like careers worth of material. So they'll be looking at these for a very long time. This is the first time that NASA brought back material from an asteroid you might remember. So they'll definitely be digging into these for a while. So Casey, why did they go to that asteroid in the first place? So this is an asteroid that a lot of people kind of just have their eyes on. There's a very slight chance that this asteroid could be on a collision course with Earth in like 2180 something. It's kind of a long shot, but there is a chance. And so NASA or other kind of space agencies might want to try to knock this asteroid off course. And so they need to know a little

bit more about, you know, what it's made of, what they might need to do to kind of redirect it. So that was one of the reasons that they decided to go and check out this asteroid in particular. I cannot think of a better reason to go, right? Love that they're on top of it. Let's talk about a different kind of space carbon, and I'm talking about the news this week about a missing space tomato. I'm not making this up, right? There was a missing space tomato. How do you get a tomato in space?

It's not a punchline of a joke, you know? I know. So there was this mission on the International Space Station where researchers were trying to grow tomatoes in space, kind of better understand how that might work. and the astronauts were harvesting the tomatoes, but they were told, don't eat the space tomatoes because there could be fungal contamination. But a few months ago, this one astronaut got back from the space station, and one of the tomatoes was missing, and everybody thought that he ate it. Really? Nobody believed him. Yes, he was like, no, I didn't eat the space tomato.

Search me. I know. He was like, I swear. So it's a missing space tomato. They found the missing space tomato. There's no, they wouldn't say like where it was. It was apparently in a little plastic bag. But the missing space tomato has been found. So NASA astronaut Frank Rubio, his name has been cleared. Wow. He did not eat the space tomato. You'd hate to have that on your resume as an astronaut. I know, I know. They're like, we can't send you back to space. You might eat the experiments. Where did they find it? Was it found in this, in the international space station? or where was it? Yes, it was still on the ISS.

They're not giving details about where it was, which I think is wonderfully mysterious. That is. Speaking of mysterious, great segue, Casey, thank you. An unusual frog with a special type of camouflage, special type. What kind of type are we talking about? Yes, I love this story. This frog camouflages itself by looking like poop,

which is just delightful. So it's this species of frog called Wallace's Flying Frog. And so these frogs, when they're full grown, they look like a classic kind of, you know, tree frog. They're like green and have really big eyes and stuff. But it takes a long time for them to grow up and develop the toe webbing that helps them kind of soar around their flying frogs. So they fly through the tree tops. And so while they're growing up, while they're juveniles or froglets, they are a totally different color. they're red with little white spots.

And researchers have thought for a while that this coloration is to make them look a little bit like the poop of birds and bats that eat fruit. What's the advantage of looking like the poop of something? I guess it's not very appealing to predators. And so this study that was in the news this week, researchers took a bunch of little wax models of these froglets. And they basically looked at what birds would attack. So would they attack ones that were green, ones that were red, and then ones that were red with the little white splotches to look like poop? And those red with white splotches, which is what the froglets look like, those were attacked far less often than the green or the red ones. So it seems to be a pretty effective mode of camouflage.

Well, Casey, you always bring us some really interesting stuff to talk about and certainly stuff that around this evening, at the end of the work week, we have something new to bring up. Bring it up at all of your parties, all of your holiday parties. I certainly will. Okay. I love it. Good. We'll follow your lead, Casey. Thank you for taking time to be with us, as always.

Thanks so much for having me. Casey Crownheart, climate reporter at MIT Technology Review. Hi, Ira here, reminding you that Science Friday has a dollar-for-dollar donation match, which means that any donation made through December 31st will be doubled. Yes. So now is the time to head over to ScienceFriday.com slash support and make a gift. Our 2024 programming depends on the generosity of our fans and listeners. Again, that's ScienceFriday.com slash support.

And thanks. As we approach the shortest day of the year, for some, the winter is an especially challenging season. About 5% of adults experience seasonal effective disorder, also known as S-A-D. My next guest is researching why some people are more susceptible to seasonal depression and the most effective treatments. Dr. Catherine Rockline is an associate professor of psychology at the University of Pittsburgh based in Pittsburgh, Pennsylvania.

Welcome to Science Friday. Thank you. Thanks for having me. Oh, it's nice to have you. Can you give us a definition of what seasonal effective disorder is? It actually has all of the same symptoms as non-distance. seasonal depression, but it occurs during particular season. So we usually see onset in the fall or winter and remission in the spring and summer. And can you give us a reason why this happens seasonally? Well, so what we're researching in my lab is whether or not some people are more or less

sensitive to the light in our environment. When it comes to, you know, weather and climate, the factor that seems to be most important in triggering sad is the length of the day, so the number of minutes from dawn to dusk. But, you know, in Pittsburgh, as well as many other places, we all undergo the same shortening of days and darker skies, more rain, more cloud cover, but only a fraction of individuals develop depression. So the theory is that some individuals are just more sensitive to those lower light levels. And in summer, when light levels are high enough, it may not be an issue, and days are nice and long. But when the light levels and the day is dropped below a certain threshold, then individuals may be more vulnerable to developing depression. Does it have something to do with

how responsive your eye is to light? Well, that's what we're wondering. It could be how responsive of your eyes to light, or it could be how responsive your brain is to that information from the eye. So I decided we should just start with the eye because it's step one in that neural pathway. And when I started graduate school, Iggy Provencio and Mark Rolag had just discovered a class of cells in the retina that nobody knew had existed before this was 2001. And they discovered a class of cells that are sensitive to light that are not the rods and cones. We used to think it was just rods and cones, but they discovered that there are these retinal ganglion cells that are sensitive to light. Oh, really? Wow. And they send their axons to the circadian clock in the

brain. So immediately, everybody's studying circadian rhythms and sleep and mood disorders got really interested. And I've been trying to find out if there's anything about these cells that differs between individuals and could explain why some of us develops that and some don't. So the cells, they wind up in an emotional part in the brain? What part of the brain? Well, there are many different parts of the brain that these cells seem to project two. One is the circadian clock, and the circadian clock then has impacts on mood centers of the brain. But these cells do seem to project two parts of the perhabanula, which is directly involved in mood, as well as the amygdala. Wow. Is seasonal depression then different from depression during, let's say, other times in the year? Yeah, that's a really

good question and it's really hard to answer. I would say that people are vulnerable to different triggers. So inside, the main trigger is falling light levels. In other kinds of depression or other forms, people might be vulnerable to things we call negative life events, like losing a job or losing a family member. And the thing is, though, that you don't have to have just one of those vulnerabilities. Some people have multiple vulnerabilities. So we think that the difference might be more in what starts off the episode. And how might your research into SAD help scientists better understand other types of depression? So the reason why studying SAD might be helpful for all kinds of depression is that we can

predict when it will begin and when it will remit. So I can do a research study where I look at individuals who are depressed and then I can do similar measurements of all kinds of biomimic. markers and psychological factors when they're in a remitted state. So that allows me to determine what pre-existing risk factors are, as opposed to things that are just correlated with having depressive episode. It's a lot harder to predict when other types of depression will occur and when they'll remit. I'm just thinking maybe, you know, if you're bipolar and that might be a trigger for you, you know, that sort of stuff. Yeah. So bipolar is interesting. What

we've been talking so far about is unipolar depression where people just experience depressive episodes and then a return to kind of a neutral mood. In bipolar disorder, that's actually very seasonal. Almost half of people with bipolar disorder have depressive episodes that follow a seasonal pattern occurring in fall, winter, as well as those episodes of mania in the spring and summer. So bipolar disorder might actually be more seasonal than unipolar depression. Okay, so what are the most effective treatments for SAD then? Well, one of the most beneficial things is that there are up to three treatments that have a good evidence based in SAD. The one that's been studied the longest is light therapy, and that involves sitting in front of a bright light,

or what they have now, which are visors that you wear, that have little light diodes that point the light directly at your eyes. So this is helpful and they even have some that go on the visor of your car so that you can be getting light therapy while you commute or while you are running around the house in the morning or if you have some other kind of morning routine that prevents you from sitting still in front of a light box for 30 to 45 minutes in the morning. Yeah, that's that's probably hard to do for most people who want to get out of the house. Absolutely. So light therapy is effective for about half of people with SAID, which is actually a better response rate than antidepressant medications. And then the third type of treatment is cognitive behavioral therapy for SAD or CBT SAD. And that's similar to cognitive behavioral therapy for depression, for non-seasonal depression, except it. It adds a few different aspects that are specific to coping with the seasons.

And how effective is that to talk? compared to the lightbox therapy? It's better. And what the most interesting thing is that it has what we think are protective effects in subsequent years. So if you do light therapy and it's effective in year one like this winter, then you would just start it up again next winter and you'd have to use it every winter to get the effects.

But with CBT sad, it looks like if you were to do 12 sessions of CBT sad this winter and then did absolutely nothing next winter, your risk of a sad episode is lower. Dr. Rockline, you're looking at the genetic components of seasonal depression. What is the research question you're currently trying to answer? I mean, does it run in families? Yeah, some portion of sad is genetic. It's about 33%.

And I am looking at the gene for the light-sensitive molecules in those cells in the eyes, we were talking about earlier. So I'm wondering if maybe the protein there that's sensitive to light, it changes shape when it absorbs a photon of light, maybe that gene for melanopsin has a different sequence in people with sad, and it causes it to function a little bit differently. So that's the study we're hoping to do this January. Well, good luck, and please let us know what you find out.

I will. Dr. Cathler and Rockline, thank you for taking time to be with us. today. Thank you for having me. Dr. Rockline is an associate professor of psychology at the University of Pittsburgh. Of course, that's in Pittsburgh, Pennsylvania. And that's all the time we have for today. A lot of folks help make this show happen, including Nehima Ahmed, Lois Parsley, Emma Gomez, Sandy Roberts, Robin Kassmer. On Monday, we're talking about chin strap penguins, and their very unusual sleep schedule. You want to make sure to stay week for this one. I'm SciFry producer. Shoshana Bucksbound. Have a great weekend.