The Effects of Cannabis (Marijuana) on the Brain & Body

**Andrew D. Huberman** (0:00)
Welcome to the Huberman Lab podcast, where we discuss science and science-based tools for everyday life.
I'm Andrew Huberman, and I'm a professor of neurobiology and ophthalmology at Stanford School of Medicine. Today, we are discussing cannabis, also referred to as marijuana. Cannabis includes many different compounds that have profound impact on the brain and body. So while many of you have probably heard of THC, there are also compounds in cannabis such as CBD. And of course, there are different types or strains of cannabis, including sativa strains and indica strains and hybrid strains. And believe it or not, nowadays, there is also an entire literature, meaning a scientific and medicinal literature about type one, type two and type three strains. I'll explain what all of that is and how they work. We'll talk about some of the medicinal applications of different strains of cannabis and combinations of cannabis strains, as well as some of the potential health hazards of cannabis use. I want to emphasize that any discussion about cannabis has to be framed within the context that the legality of cannabis varies tremendously depending on where you are in the world. So depending on which country you're in and even which state you're in or which area within a country possessing and using and certainly selling cannabis can be either highly illegal or entirely legal or decriminalized or largely overlooked. You of course are obligated to know what those local laws are for you, where you live and where you travel. With that said, today's discussion really will include a full picture as to where cannabis and the various and even very specific compounds within cannabis can be extremely useful in the treatment of some ailments and where certain compounds in cannabis can be extremely dangerous for certain individuals to use, in particular individuals that have pre-existing genetic propensity for psychosis. That theme is going to come up again and again, but we are also going to talk about the role of cannabis in anxiety, in depression, both positive and negative effects. We'll talk about sex differences in terms of women versus men and how they react differently to cannabis. And I would be entirely remiss if I didn't include a conversation about cannabis, meaning THC, CBD, hybrid strains, et cetera, in creativity and different modes of thinking. Because as many of you probably know, or at least have heard about, cannabis can impact the way that we think, the types of memory systems we can access, and what's called convergent and divergent thinking, which is one way of conceptualizing what is commonly referred to as creativity. So today's discussion is going to include a lot of information, but I promise to make it clear and accessible to all of you, regardless of whether or not you have a background in biology or not. And today's discussion will also be quite nuanced. You'll find me routinely reading directly from specific research papers, something that of course we always do on this podcast. But today I'm really going to dig into some of the finer points of the methodology in papers and some of the statistics that were used and the specific populations of people that were studied. Because as it turns out, there are instances that we will discuss in which the use of cannabis can be immensely beneficial to one group and yet can be entirely detrimental to another group, even at equivalent dosages and depending on a number of different factors. So we will discuss what those factors are. Just to give you a brief overview of the kind of structure I'm going to put on today's episode, we will review of course cannabis and its various forms. I'll talk about some of the biology, but we are going to really drill into how dosage, that is the concentration of THC relative to CBD impacts whether or not cannabis is going to have one effect or another. We will also talk about the frequency of use, daily use, multiple times per day use, weekly use, or monthly or occasional use. We will also talk about different professions and how some people may have a little bit more leeway in terms of whether or not they decide to use cannabis or any of its various component chemical constituents, that is CBD or THC, et cetera. And for other professions, it might be entirely inappropriate because of the particular kinds of cognitive tasks those professions demand. We will also talk about genetic predisposition, again, sex differences, hormone effects, and I will also touch on what I think is the most important variable in determining whether or not cannabis is right or wrong for you. And that is your age at which you are considering starting or continuing use or ceasing use. What I can assure you is that by the end of today's podcast, you will have a quite thorough understanding of cannabis, how it works, what it does, what its potential benefits can be, what its potential hazards are, and whether or not it's right for you and the people that you know. Before we begin, I'd like to emphasize that this podcast is separate from my teaching and research roles at Stanford. It is, however, part of my desire and effort to bring zero cost to consumer information about science and science related tools to the general public. In keeping with that theme, I'd like to thank the sponsors of today's podcast. Our first sponsor is Element. Element is an electrolyte drink with everything you need and nothing you don't. That means plenty of salt, magnesium and potassium, the so-called electrolytes, and no sugar. Now, salt, magnesium and potassium are critical to the function of all the cells in your body, in particular to the function of your nerve cells, also called neurons. In fact, in order for your neurons to function properly, all three electrolytes need to be present in the proper ratios. And we now know that even slight reductions in electrolyte concentrations or dehydration of the body can lead to deficits in cognitive and physical performance. Element contains a science-backed electrolyte ratio of 1000 milligrams, that's one gram of sodium, 200 milligrams of potassium, and 60 milligrams of magnesium. I typically drink Element first thing in the morning when I wake up in order to hydrate my body and make sure I have enough electrolytes. And while I do any kind of physical training and after physical training as well, especially if I've been sweating a lot, if you'd like to try Element, you can go to drinklmnt.com. That's lmnt.com/huberman to claim a free Element sample pack with your purchase. Again, that's drinklmnt.com/huberman.