Marijuana legalization,
as our governments
begin to accept it as part of our society,
we need to understand how it affects
our health.
Researchers have been looking for a long time
at how cannabis can affect mental health.
This video will investigate the link between marijuana and
schizophrenia. So lay back, and get ready for a trip!
Leading medical researchers are coming to the conclusion,
that marijuana, pot, grass,
whatever you want to call it.
It is probably the most dangerous drug in the United
States and we haven't begun to find out...
The 1980s, the era of Michael Jackson,
the Cosby Show, and The War on Drugs!
It was in the 80s that marijuana research really took
off for the first time.
Thanks in part to President
Ronald Reagan's mission to remove it from the American psyche.
The first time it was a Hot Topic.
The public wanted to prove the President right or prove
the president wrong.
The most important study in the Reagan Era came,
in 1987,
from Andreasson and colleagues.
In a longitudinal cohort,
study of 45,000,
Swedish citizens,
who was found that heavy marijuana users
were six times as likely to develop schizophrenia,
than someone who has never smoked.
This article has been cited,
796 times,
as of November 2020,
obviously,
it left a great mark on public and expert opinion.
In fact,
the study was so popular that they did it twice.
Well, kind of. Two years, later in 1989 Andreasson and
colleagues,
followed up with a deeper analysis of a subset of
the original cohort.
Their conclusions
was the same. Marijuana use is connected to developing schizophrenia.
But what Andreasson and colleagues could not answer for,
is something called "causality".
In other words,
are we sure that X caused Y and not that
Y was there and happen to have X?
Their studies did not take into account important causality questions.
Did schizophrenia symptoms always precede marijuana use or are schizophrenics
more prone to using marijuana?
Perhaps for self-medicating? Were schizophrenics
also abusing other drugs, like alcohol?
Today,
researchers would say that their epidemiological findings,
show a strong correlation, without proof of causation.
Welcome back from your trip.
So what have you learned today?
We started this video by criticizing the earliest studies connecting
schizophrenia and marijuana use.
Then we learned that over 30 years,
scientists have come to address
some of these criticisms. Although the relationship is still not
clear-cut.
So does marijuana use, cause schizophrenia?
Our answer today, is rather unsatisfying:
maybe.