Marijuana: Legalize or not? (Patreon)

[This is a transcript with references.]

More than 200 million people use marijuana. It’s the most widely used drug worldwide, after alcohol, caffeine, and YouTube. In contrast to those three, marijuana is illegal in most of the world. But an increasing number of countries have begun legalizing cannabis, first for medical use, and now also for recreational use. Several US States, including Washington and Colorado, began legalizing recreational use starting in 2012. Canada legalized in 2018. And Germany, as the first country in the European Union, is about legalize it. Is this a good idea? And if they move ahead, should I try it? That’s what we’ll talk about today.

First things first, cannabis is a plant genus. That’s genus, not genius, and it means that there’s more than one of those. Hemp, for example, is a type of cannabis plant that you can make T-shirts of. But today we’re not interested in T-shirts, we’re interested in chemistry.

Cannabis contains two chemical substances of interest, that’s tetrahydrocannabinol, THC for short, and cannabidiol, CBD for short. THC is the main psychoactive compound of cannabis. It affects perception, cognition, and behaviour, and is responsible for the “high”. CBD is believed to have medical uses – we’ll talk more about that later.

Cannabis with a low concentration of THC is legal in most countries, though the limits differ somewhat from one place to the next. Hemp, for example, is low in THC, so your T-shirt is probably legal, and there’s little use in trying to smoke it.

Cannabis plants are dioecious, which means male and female plants are different. The highest THC concentration is in the dried flowers of the female plant, so breeders will usually weed out the male ones, regardless of their chosen pronouns.

Marijuana refers to the dried flowers, leaves, stems, and seeds of the cannabis plant. The stuff can be smoked, vaporized, or used to make edibles, usually that’s something sweet to mask the taste, like cookies, gummies, or candy. Hashish, or hash, is a concentrated form of marijuana that’s made from certain parts of the cannabis plant. Making hash is rather labour-intensive, which is why it’s usually more expensive than marijuana.

The word “marijuana” probably originated from an old Mexican word which means “prisoner” or “slave,” likely because cannabis plants were associated with Mexican workers who produced ropes and textiles from them. The spelling “marihuana” with “h” was used in the United States in the early 20th century to associate the drug with Mexican immigrants. It’s rarely used today and actually seeing the origin of the word I’m somewhat surprised no one’s yet tried to cancel it. Other common terms used for marijuana are dope, pot, grass, or weed.

There are more than 700 strains of recreational cannabis with fancy names such as Green Crack, Gorilla Glue, Death Star, or Laughing Buddha. Breeding of cannabis plants has much increased the THC content and it’ll almost certainly continue to increase some more. The THC content of marijuana sold in the US has increased by more than a factor 3 in the past 30 years, and in Europe by about a factor two, so the marijuana your kids buy today is much more potent than the one you used to smoke.

Marijuana use is incredibly common. According to the 2022 World Drug Report by the United Nations, it’s used in virtually every country in the world. Twenty years ago, men were twice as likely to use cannabis than women, but by now the gender gap has almost closed.

In the USA almost 50 million people used it in 2019. It’s most widely used among young adults in the age group 18 to 25 where more than one in three uses marijuana. In the US, Marijuana use is increasing in all age groups except for the youngest. North America is also the region of the world with the presently highest prevalence of cannabis users, about 17 percent of adults, followed by Australia with about 12 percent. Australia legalized access to cannabis products for medical purposes in 2016. Since then, the number of applications has increased exponentially: While in 2016, only 15 applications were submitted; In 2018 it was already more than two thousand and in 2021 more than a million. If we extrapolate this trend, by 2030, Australia will turn into a big bong.

Usage in Europe is much lower, but it’s also increasing. A 2021 paper published in The Lancet Regional Health.found that between 2010 and 2019, past-month cannabis use increased among European adults from 3.1 to 3.9%. The highest number of cannabis users in Europe are in Spain, followed by France, and the percentage of users has been increasing in the past decades in all European countries, except Poland.

Cannabis use is by no means news. Cannabis was one of the first plants that humans have cultivated. It was mentioned already more than four thousand years ago, engraved in stone in some of the pyramids. Molecular analysis has found residues in ancient pottery and suggests that the Greeks and Romans put it into wine. Almost all the old languages have a word for cannabis. Historians say the Egyptians administered it by mouth, rectum, and vagina, which will hopefully give Gwyneth Paltrow some better ideas than jade eggs.

Depending on whether you smoke, inhale, or chew gummies, THC and CBD enter the blood stream either through the lungs or the digestive system. It takes much longer for the compounds to be released from edibles, which is why that ways it’s easier to accidentally overdose.

THC is able to cross the blood-brain barrier and occupies cannabinoid receptors in the brain. This affects the release of some neurotransmitters which the brain uses for regulation and leads to changes in perception, mood, and cognitive function.

This was the simple story. The more complicated story is that there isn’t just one type of THC, and it doesn’t just occupy one receptor. The molecule THC comes in slightly different arrangements of atoms which are called “isomers”. The most relevant ones you need to know of are Delta-8 and Delta-9 THC. Since they bind to receptors with different strengths, they have somewhat different effects.

Most of the THC in cannabis is of the type Delta-9 THC and it’s responsible for the drug’s characteristic psychoactive effects. Since it affects many different parts of the brain and people’s brains are all somewhat different, experiences differ, but the effects include euphoria, increased appetite, an altered sense of time and reality, changes in pain perception, and relaxation. Some people find it to decrease anxiety, but some report increased anxiety and paranoia, especially at high doses.

THC also affects the functioning of the hippocampus and orbitofrontal cortex, which are the brain areas that we use to form new memories and shift attentional focus. This is why marijuana use impairs thinking in general and memory formation in particular, but don’t worry, you can rewatch this video as often as you want.

THC also disrupts the function of brain areas that regulate balance, posture, coordination, and reaction time. That’s why people who have used marijuana may not be able to drive safely and may have problems playing sports or engaging in other physical activities.

Cannabis also contains small amounts of Delta-8 THC, which you may have seen advertised in some products. It’s difficult to directly extract from the plant, but the more common Delta-9 THC can be chemically converted to Delta-8 THC.

Delta-8 THC is still psychoactive, but it has a milder effect. Users report it to be less intense, more relaxing, and less likely to be anxiety-inducing than Delta-9 THC. If Joe Rogan is Delta-9, then I’m Delta-8.

That’s THC. CBD now does not bind the same way to cannabinoid receptors in the brain. Exactly how it works is still subject of research, which is the academic way of saying “God only knows”, but scientists believe it interacts with other receptors, including serotonin receptors.

The marijuana that you might buy in the street normally contains all of those chemical which is why most of the available data on long-time use is on cannabis in general and not on one of its specific compounds. So what do we know about the long-term risks?

First of all, smoking is generally not good for the lungs, pretty much regardless of what you smoke.

Second, cannabis can become addictive. This means that some users begin to develop a tolerance to the drug and must use it in higher doses to get the desired effect. They might find that the regular use of cannabis negatively affects their daily life, and they might experience withdrawal symptoms if they stop using it. Just what the withdrawal symptoms are differs from one person to the next, but it typically includes irritability, insomnia, and loss of appetite.

According to the National Institute on Drug Abuse in the US, about 9 percent of people who use cannabis will eventually become addicted to it. The risk of addiction increases to about 17 percent for those who start using cannabis in their teens, and 25-50 percent for those who use it daily.  

For reference, according to the world health organization, in the United States about 14 percent of people age 15 and up had an alcohol use problem in 2016. About 10 percent are lifelong abstainers, which means the fraction of people who try alcohol and get a problem with it is about 15 percent.
In the UK about 8 point 7 percent have an alcohol problem which is about 10 percent of those who drink. And in Russia, about 29 percent of those who drink have an alcohol problem.

This might make it seem like the risk of developing an alcohol problem is somewhat higher than the risk for cannabis, but these numbers are difficult to interpret because they conflate the effect of the drug with its use being socially accepted.

And then there are the long-term consequences. When Canada was preparing for legalizing cannabis for recreational use, its government commissioned a study of the drug’s potential harmful effects. In the 2018 paper that followed the study, they presented an analysis of 68 reviews on cannabis. Of these, 62 showed associations between the drug and various adverse outcomes, including impaired driving, increased risk of stroke and testicular cancer, brain changes that can affect learning and memory, and a particularly consistent link between cannabis use and mental illnesses involving psychosis, especially in people already at risk of mental illness.

A paper published a few months ago in The Lancet used the data of a cohort of about 1000 people in New Zealand. The study found that, after correcting for other sociological and medical factors, long-term cannabis users showed statistically significant accelerated biological ageing. There were less able to manage health, financial, and social demands than non-users.

And multiple studies have found that the risk for detrimental effects on mental health and addiction is substantially higher for adolescents.

Another good number to gauge the risk of cannabis is to look at the number of people who are hospitalized because of cannabis consumption. In Germany the percentage of cannabis users has fluctuated around roughly 6 percent in the past decade, that’s about 5 million people. The number of hospitalizations meanwhile has increased to roughly 19,000 per year. Almost half of the hospitalizations are for dependence syndrome, followed by psychosis and acute intoxication

If you just divide the number of hospitalizations by the number of users you get about zero point 3 percent. But this isn’t the fraction of users who end up in the hospital because it might be that the same people end up in the hospital repeatedly, so be careful with interpreting this number.

In the US, the number of users has slightly increased, but the number of cannabis-related visits to the emergency department has increased much faster. If you just divide those numbers by each other, you get a ratio about ten times as high as that in Germany. But those numbers should not be compared because not everyone who goes to the emergency department also ends up in the hospital, and “cannabis associated” might mean something different in the US than in Germany. In any case, in both countries the number of hospitalizations has been steeply rising. Why this happens is currently unclear, might have to do with legal changes or with the increasing THC content.

The most common uses of cannabis and cannabis-derived substances is to treat insomnia and pain. The evidence that it works for either is, to make a long story short, moderate to insubstantial.

A review paper from 2021 found that, in the short-term, THC improves sleep but when used regularly it impairs it. A review from February last year found that cannabis products led to a moderate improvement in sleep quality for people with chronic non-cancer pain. However, they also found a statistically more significant increase in side effects that included dizziness, fatigue, nausea, and a dry mouth.

In 2019 a group of Canadian researchers published a systematic review in the Journal Systematic Reviews which reviewed 72 other systematic reviews. It sounds to me like the time’s come for a Ponzi scheme of systematic reviews.

They found that about half of the reviews had very low quality. When they limit the analysis to papers that the authors consider to be of moderate or high quality, then the effect of cannabis on pain relief was small but better than a placebo. The authors also found that more than half of the reviews reported minor adverse effects, the most common being psychosis, but also drowsiness and dizziness.

However, the effects of cannabis are very individual, since the stuff affects so many different parts of the brain in ways that aren’t entirely understood. This means that the variation in results is large and it’s quite possible that if the stuff works for you then that’s not your imagination, you’re just a statistical outlier.

Okay so we have seen that cannabis isn’t exactly harmless, then let’s look at the talking points for and against legalization.

First of all, that cannabis use is illegal doesn’t always mean much because in some countries, including Germany and several US states, possessing and using it isn’t persecuted. In these cases, most of the changes that legalization brings concern the production and sale. But of course, this has further consequences.

The first and obvious argument against legalizing recreational marijuana is that it’s unhealthy. The obvious counter argument is that lots of things that unhealthy are also legal, like watching 20 of my videos in a row, after which you’ll walk around for a day cracking dumb jokes with a German lisp. Definitely not healthy. But totally legal.

A variant of this argument has it that decriminalizing cannabis will lead more people to use it, and thereby increase the damage to public health. And indeed, following legalization in Canada, they saw a mild increase in cannabis use, overall from about 22 to 26 percent. Interestingly enough most of that increase comes from women. There was little increase among adolescents, it mostly came from adults.

In the USA, it was similar. What this means is another question though because as we saw earlier, cannabis use is increasing pretty much everywhere, whether or not it’s been legalized. There is also some evidence to suggest that legalization decreases opioid use and alcohol abuse among teenagers.

The next argument is that cannabis is a gateway drug to worse addiction. Indeed, multiple studies have found that cannabis use, especially when begun at young age, is positively correlated with later abuse of other drugs. But correlation doesn’t mean causation. The issue is that some people might be predisposed to substance abuse for multiple reasons including social factors and mental problems, and they’d have ended up with harder drugs with or without first taking cannabis. A clear causal link has so far not been established.

Another worry is that cannabis use increases crime, though there is little evidence to support this claim. A 2019 paper by a group of American researchers found that legalization in Washington and Colorado had no noticeable effect on the crime rate.

Then there is the worry that more cannabis use increases the risk of traffic accidents caused by people driving under the influence. Data from the United States and Canada does not support this.

But somewhat worryingly Canada reports a large percentage of cannabis users who do drive after consumption, almost a third, but this fraction has consistently declined in all groups since legislation which suggests that it takes some time for people to adjust to the new laws.

What lesson other countries should draw from this isn’t all that clear. The consequences of legalization on use, traffic, and crime depend very much on just exactly what the law says, and how it’s enforced, and also on what the social norms are. So just because it turned out one way in one place doesn’t mean the same would happen elsewhere.

Finally, there is the argument from economics that if it’s legal you can tax it, and then you can use the money to fill potholes, no pun intended.

The German government wants to legalize the use and sale of cannabis. But the European Union has a law that makes the production illegal. Which is why the growth of marijuana plants, at least for now, will be limited to three plants per adult. That’s three female plants. You can grow male ones as much as you like, no one cares about them.

Should I try it? Having read all these papers, I think I’ll hold off until I’m retired because for the time being I still need my brain. But since the Germans will soon be able to sell and buy cannabis, yet be prevented from producing it, maybe it’s a good time to find some cannabis producers overseas and buy their stocks.