We started to use the term marijuana

mainly to associate it with Mexican Americans,

in an effort to vilify the drug

because cannabis had been around forever

and many Americans were familiar

with the effects of cannabis.

And so you couldn't make these incredible stories up

about cannabis itself, but really they're the same thing.

[intense jumpy music]

I'm Carl Hart, professor in the departments

of psychiatry and psychology at Columbia university.

I study the effects of drugs in people.

There's so much misunderstanding about drugs,

particularly recreational drugs.

And today I'd like to clear up some of the information

and to bunk many of the myths that many people hold.

[intense jumpy music]

Marijuana is a gateway drug.

When we say gateway drug,

we mean that using marijuana will cause someone

to go on to use so-called harder drugs,

like cocaine or heroin.

When we think about the people who use heroin,

more of those people have used marijuana beforehand.

That's certainly true.

But when we look at marijuana users in total,

the vast majority of marijuana users do not

go on to use cocaine or heroin or any other drug.

So this notion that marijuana is a gateway drug confuses

correlation with causation.

Correlation are just variables that may go together.

If it's raining outside,

you might see more umbrellas that go up

than when it's not raining.

And that's a correlation between umbrellas and rain fall.

But no one would say the umbrellas are causing the rain.

That's correlation.

Causation is when you have a variable

that causes another variable.

For example, the last three presidents of the United States,

Bill Clinton, George Bush,

and Barack Obama all smoked marijuana

when they were young men.

It would be like saying that marijuana is a gateway drug

to the White House.

It's not true.

That's the difference between correlation and causation.

We know for sure that marijuana is not a gateway drug

because the vast majority of marijuana smokers

never go on to using any other drugs.

If it was a gateway drug,

then we would have the majority, if not all,

going on to try harder drugs.

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PCP gives superhuman strength.

One of the ways PCP acts on the brain

is that it interacts with a neurotransmitter

called glutamate.

Glutamate is the brain's sort of major,

excitatory neurotransmitter.

It causes actions and PCP blocks one

of the glutamate receptors.

So it prevents glutamate from acting at that receptor.

When people actually give PCP to research participants

in the lab,

you have never seen anything remotely resembling superhuman

strength or any of the other sort of effects

that have been attributed to PCP,

like aggression or violence.

This notion that PCP causes superhuman strength

comes largely from police reports

or police stories, police anecdotes,

where you may have heard them say that they have to shoot

someone 28 times in order to bring them under control.

There is absolutely no evidence of that.

Can any of these illegal drugs induce violence?

And the answer is emphatically, yes,

in people who were already violent.

But in general, the drugs themselves

are not producing violence.

[intense jumpy music]

Drugs are more addictive than alcohol.

To be clear, alcohol itself is a drug.

Many of the criteria that determine whether or not

someone is addicted, depend upon the legality of the drug.

You have to hide cocaine use

because that's not as socially acceptable as alcohol.

So all of that impacts whether or not someone

becomes addicted to a drug.

Once people become addicted to alcohol

versus something like cocaine or something like heroin,

if they stop abruptly taking alcohol,

they can experience alcohol withdrawal

and alcohol withdrawal can lead to seizures,

which can cause convulsions,

brain damage and ultimately death.

When they withdrawal from something like cocaine,

you don't get any of these physical effects

that can cause deaths.

The same is true with something like heroin.

Heroin doesn't cause death upon withdrawal.

Only alcohol, of these drugs,

can cause death upon withdrawal

if withdrawal is not done in a medical setting,

that is, with someone who is heavily dependent on alcohol.

[intense jumpy music]

The opioid crisis is getting worse.

Well, that's not true.

And in fact, I would even suggest

that we were not experiencing a crisis of opioids.

Instead, we were experiencing a crisis of ignorance.

Whenever we talk about the opioid crisis,

we have to differentiate what we mean.

Are we talking about deaths related to opioids

or are we talking about addiction related to opioids?

If we think about addiction,

the vast majority of people who use opioids,

particularly say prescription opioids,

a very low percentage of people become addicted.

Something like heroin,

where you have the higher sort of addiction rates

and that's about a third at most,

that's not necessarily a crisis

because very low number of people use heroin.

When we think about the overdose crisis,

that we want to call it that,

we've seen numbers in the United States as high

as 70,000 people dying from opioids every year.

And that's just not true.

The largest amount of people who die

from an opioid related drug is maybe 45,000 per year.

That's at it's peak.

But when you even go into that number,

what you discover is that the vast majority

of those people had another drug on board

in addition to an opioid,

some other drug like a benzodiazepine,

alcohol, or an anti-histamines or something else

was on board.

So whether or not the opioid actually caused the death,

we don't know.

[intense jumpy music]

Marijuana doesn't have any medicinal use.

The federal government has a medical marijuana program

in which small numbers of people are enrolled,

such that they receive marijuana

from the federal government for free every month

in order to deal with some medical element,

ranging from things like glaucoma or some pain.

So marijuana has been shown in a number of studies

to increase food intake, to decrease pain,

and a growing number of other medical elements

are being tested.

For example, components of marijuana have been shown

to be effective for decreasing seizures.

CBD recently has become one of the most talked about

compounds in marijuana.

We have known marijuana's effects for at least 70

something years or so.

In 1944, Mayor LaGuardia in New York City

released an extensive study of marijuana's effects

and basically conclude what we know now.

Marijuana doesn't lead to these long term negative effects

that people said.

It doesn't lead to violence.

The LaGuardia Report at 1944 drew that conclusion.

And it's the same conclusion that research today draws.

The federal government, the Bureau of Narcotics in 1937,

push for the ban of marijuana in part,

because it was associated with groups

that we don't like in the United States,

Mexican and black folks.

It had nothing to do with marijuana's pharmacology

and by pushing for marijuana to be illegal

or banned or outlawed, what happened too,

was that the Bureau of Narcotics budget increased.

Marijuana is illegal today at the federal level

for political reasons, not pharmacological reasons.

There are so many drug myths out there

and the myths themselves do more harm than the drugs.

Most people don't use drugs,

therefore they don't know about drugs.

And ignorance is determining how many people

think about these drugs in part

because these myths lead to bad policies

and these policies cause increased rates

of incarceration and deaths, not from the drugs,

but from the policies.

Can lead to the dehumanization

and the stigmatization of people.