Sir Robin
Murray, the author of this month’s Cerebrum article, “Appraising the Risks of Reefer Madness,” first began to wonder in the 1990s why more and more young
people were seeking treatment for psychotic symptoms in the United Kingdom.
Many had been excellent students and athletes and socially active when—with no apparent
family history of psychosis or trauma— they had started to develop cognitive
problems and then hallucinations and delusions. Common in many of their stories
was one familiar refrain: they were known to have smoked huge amounts of
marijuana. We asked Murray, M.D., professor of psychiatric research at the
Institute of Psychiatry at Kings College in London and former president of the
European Psychiatric Association, to embellish on some of the points he makes
in his article.
Is there a reason why your research
pointing out suspected problems associated with cannabis use were met with such
skepticism?
Robin Murray: Many neuroscientists and
psychiatrists who think of themselves as liberals have long felt that the
prohibition of marijuana is a bad thing. Maybe it’s because they tried cannabis
a few times in the 1960s or 1970s, found that there weren’t any side effects, and
concluded it was safe. Their reaction isn’t very different from the way many
people thought about cigarettes in the 1950s, when the first studies first
started coming out about the risks and many smokers thought the findings to be
ridiculous. At the time, there were even advertisements that said that menthol
cigarettes had a cooling effect that was good for a sore throat.
Do you think we’re making a mistake
in decriminalizing marijuana and making it legal in some American states?
I have no problem with decriminalization.
It’s daft to waste money prosecuting people for smoking marijuana and then sending
them to jail. In the UK, although cannabis is officially classified as illegal,
it’s difficult to get arrested for marijuana unless you blow the smoke into a
policemen’s face!
On the
question of legalization, we just don’t know enough yet and need to wait and
see. There are really three big questions:
1). Will marijuana remain a cottage industry,
or will it become a commercial industry like tobacco, with all the advertising
and branding that goes along with it? It’s sad that Bob Marley, so long an icon
for the underprivileged, is set to be the name of an international brand of marijuana
supported by big business.
2). What would happen regarding teenagers?
Although no one is proposing that we legalize it for those in their early teens,
would legalization lead to increased consumption in this most vulnerable group?
Some of the early evidence from the states that have legalized marijuana or
medical marijuana suggests that consumption among teenagers is going up.
3). What about education? We’ve been very
successful in educating people about the risks of cigarettes, but very
unsuccessful about educating people about the risks of alcohol. If we had widespread education along with
legalization, then perhaps consumption might follow the cigarette rather than
the alcohol model.
Most people who smoke
marijuana have no idea where it comes from, the kind of strain it is, what has
been sprayed on it, and other inherent dangers. Would government regulation
lead to making it safer?
One argument for legalization is
that it would be like a bottle of wine or beer in the sense that a label would
disclose the concentration of tetrahydrocannabinol (THC) and cannabidiol
(CBD), and people would
have a better idea about its potency. The label might also advise that the
cannabis be used with caution, warning that it is not a good idea to use huge
amounts. However, that kind of warning on alcohol products doesn’t seem to have
much of an impact on consumption. Altogether I am content that Britain is far
away from Colorado and Washington so we can afford to wait and see what happens
over the next few years before we make our own decision regarding legalization.
Why is cannabis on the
rise in the U.S. while in Europe it is on the decline?
In countries that had high potency
cannabis earlier, such as Holland, England, and Australia, we began to see more
problems related to psychosis earlier, which led to more research and public
discussion about it. The potency of cannabis in the U.S. has been behind,
although it’s beginning to catch up now.
Your article suggests that there has
been far too little medical research on this topic.
It’s amazing how little research
there has been into the effects of long-term use. Over the last 15 years, a lot
of neuroscientists have become interested in the effects of the different
cannabinoids; some very good research has been carried out at a basic level and
a little on possible therapeutic uses. But in terms of clinical research on the
possible negative effects of use on humans, there has been hardly any—maybe
three or four groups in the world started seriously looking at this about 10
years ago. One is in the states; Cyril D’Souza and his colleagues at Yale.
Is there anything else
that concerns you about cannabis?
The next big issue will be synthetic cannabinoids, synthetic
cathinones, (that are similar to amphetamines) and other mind altering drugs
that are available on the internet. Governments try to ban them and, as soon as
they do, chemists slightly change the molecular makeup and introduce a new synthetic
form for the market. In 2006, you couldn’t find synthetic cannabinoids, now
these drugs are just mushrooming. According to the European Monitoring Center,
there are over 500 synthetic cannabinoids available.
A huge human
pharmacological experiment is going on where people are throwing all sorts of unknown
chemicals at their brains. Of course this is of great interest to neurochemists
and psychiatrists interested in studying the effects. When I’m talking with
young people, I always point out that they always seem so concerned about what they
put on their faces in terms of the latest moisturizer or after-shave lotion.
But I always ask them why they are not more concerned about what they throw at their
brains – many will take any tablet offered to them in a night club without
having any idea what it contains.