Subscribe to Beyond Blue on Apple Podcasts, Spotify, YouTube, or your favorite podcast player.
Show notes
As legal cannabis becomes more common and products grow more potent, what do we really know about the risks? Yale psychiatrist Deepak D'Souza explores emerging evidence on brain development, mental illness, and why some young people may be especially vulnerable. Plus, when we should think twice about the answers we get from AI chatbots; the quiet evolution of salamanders; and how exercise may help our bodies fight cancer.
Beyond Blue. Stories worth sharing. From Yale, for you.
Beyond Blue is produced by Yale's Office of Public Affairs and Communications. Portions of the podcast are recorded at the Yale Poorvu Center for Teaching and Learning.
Subscribe to Beyond Blue on Apple Podcasts, Spotify, YouTube, or your favorite podcast player.
Transcript
Dan Corcoran: Deepak D'Souza first noticed the negative impacts of cannabis on patients with serious mental illness when he started practicing psychiatry more than 30 years ago.
Deepak D'Souza: If cannabis or some other environmental cause contributes in a significant way to the development of schizophrenia, then that's something worth studying.
D.C.: So, D'Souza grew increasingly concerned when several states began adopting policies legalizing recreational cannabis in the early 2020s.
D.D.: The most important reason is that cannabis is much more potent now than it used to be.
D.C.: It was already clear that cannabis posed risks to those previously diagnosed with serious mental illnesses such as schizophrenia. But D'Souza says it can be difficult to predict who will develop such an illness in the future.
Family history is an obvious risk factor. But there may be no known family history for many young people who will develop these illnesses - and who may be extra vulnerable to cannabis.
I'm Dan Corcoran, and this is Beyond Blue. Stories worth sharing. From Yale, for you.
Just ahead, some things worth a closer look.
We've all wondered whether we can trust the answers we get from an A.I. chatbot. Sometimes, they just get it wrong. Researchers are trying to understand why, and when we should think twice about trusting the answer.
Salamanders have looked almost exactly the same for tens of millions of years. But scientists are discovering that a lot of evolution has been happening where we can't see it. We'll tell you what they just found.
And, we all know exercise is good for us. But what if it could also help our bodies fight cancer? When our muscles are working hard, they need fuel. So do tumors. And researchers are finding they may actually compete for it.
But first, as cannabis becomes more widely available, what do we know about its mental health risks? Yale psychiatrist Deepak D'Souza is here to talk about it.
Research has questioned the safety of today's legal, readily available cannabis products.
In addition to behavioral health concerns, recent reports have linked cannabis use to elevated risks of heart disease and stroke, brain developmental disorders, and spikes in emergency visits.
D'Souza says most people who use cannabis - and use it sporadically - may not experience negative consequences. But some people do, even with sporadic use.
Despite this, D'Souza says there's very clear evidence that adolescents are at risk. The developing brain in both men and women is more vulnerable to the effects of cannabis.
D.D.: Adolescence is a time when the brain undergoes perhaps the greatest change in a human being. It's a time when connections that are unnecessary are removed, and connections that are necessary are strengthened. And that's what's transforms the adolescent brain into a young adult and adult brain. That process is also a time when serious mental illness begins to first be seen.
D.C.: So, why is the adolescent brain more sensitive? D'Souza says it has to do with an important chemical messenger system in our brains called the "endo-cannabinoid system." It regulates critical bodily functions, such as learning and memory, emotional processing, sleep, pain control, inflammatory and immune responses, and eating.
D.D.: One of the important functions of the endocannabinoid system is to influence brain development. That endocannabinoid system can be disrupted by exposure to cannabis during adolescence, and that can lead to far-reaching implications on brain development.
D.C.: Despite these concerns, the United States is one of only a handful of developed, Western nations that have legalized recreational marijuana.
D'Souza says the legalization issue isn't well understood. And it's not so much about legalization. It's about commercialization.
Many city, town, and state governments are earning revenue based on recreational and medical cannabis sales. So, it's hard for them to give that up now.
But D'Souza says there's no dollar amount you can put on health.
Moving forward, he thinks policymakers can do two things. First, education.
D.D.: I was previously somewhat pessimistic about what we could do, because adolescence is a time also when people are more willing to take risks. But I think what we've seen with tobacco and smoking gives me some hope. So, in the last 15 years or so, we've been able to convince young people that smoking is no longer cool.
D.C.: Second, limit the use of cannabis by teens and young adults. So, better regulation.
D.D.: In terms of where cannabis can be sold; how it's sold; is the packaging of cannabis too attractive to young people - sometimes that's by design that the packaging is attractive, or that cannabis products are sold in ways that make it more enticing to adolescents. Having mango or pineapple flavored concentrates clearly target young people, so we can do a better job in regulating the way that cannabis is sold.
D.C.: Our thanks to Yale psychiatrist Deepak D'Souza for that conversation.
Alright, now let's get even smarter with three quick stories worth sharing with someone you know.
We've all had that moment. You ask an AI chatbot a question, it answers instantly, and then you wonder, "Can I actually trust this?"
That's exactly what researchers are trying to understand. They're studying why chatbots sometimes get it wrong, and how to recognize when an AI's recommendation doesn't actually match what a person wants or needs.
As AI becomes part of everyday life, knowing when to trust it may become just as important as knowing how to use it.
Next up, something to think about the next time you take a walk after it rains.
Salamanders have looked almost exactly the same for tens of millions of years. For a long time, scientists assumed that meant they hadn't changed very much.
But researchers recently uncovered something surprising. Salamanders that look nearly identical have actually adapted to their environments in very different ways, from tolerating heat and cold to conserving water.
Yale ecologist Martha Muñoz says evolution isn't always something we can see.
Martha Muñoz: You can generate a lot of biodiversity. A lot of selection has been happening. A lot of evolution has been happening; it's just happening under the hood.
D.C.: Finally, you already know exercise is good for your heart. Here's another reason to keep moving.
Researchers have discovered that when muscles are working hard, they compete with tumors for glucose, the fuel both need to survive. That means exercise may actually help deprive tumors of the energy they need while strengthening the body's natural defenses against cancer.
Researchers are still learning exactly how this works in people, but the early findings are promising.
That's it for Beyond Blue. I'm Dan Corcoran. Thanks so much for listening.
