Experts
ask: Can cannabis be made safer?
The Lancet
As cannabis laws become liberalised in many countries, experts writing in The Lancet Psychiatry argue that there is an urgent need to explore how cannabis use can be made safer.
The authors say that policy makers and researchers should
consider regulating cannabis potency, reducing the use of tobacco (e.g. by
using vapourisers), and exploring how the chemical composition of cannabis
could be modified to reduce harm without altering the pleasurable effects of
the drug.
In the past 40 years, the potency of cannabis has on average
doubled worldwide and there is evidence of a greater number of people seeking
help for cannabis use disorders in the UK, Europe, and USA.
Despite prohibitive laws on possession and use of cannabis being
introduced in the 1960s, cannabis use has increased in most parts of the world,
suggesting the laws have had little effect on use and abuse.
Uruguay and a number of US states, including California, Oregon, Alaska, Maine, Massachusetts, Washington, Nevada, and Colorado allow cannabis to be sold for recreational purposes. Canada is set to legalise its recreational use in 2017 and several European countries, including Portugal, Spain and the Netherlands, have lessened or abolished sanctions on possession and use.
The main active compounds found in cannabis are
delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). High potency cannabis
is high in THC with low (or absent) levels of CBD. This variety is commonly
known as sinsemilla (Spanish meaning "without seed") or sometimes "skunk."
Recent evidence suggests that CBD may protect against some of the detrimental
effects of THC such as memory impairment and paranoia.
Writing in a Personal View, the authors, from the Institute of
Psychiatry, Psychology and Neuroscience at King's College London and UCL (UK),
argue that the time has come to consider harm reduction in cannabis use.
First, the authors say more focus on the harms of tobacco is
needed since cannabis is frequently used with tobacco, particularly in Europe.
For instance, smoke-free vapourisers could help reduce the harmful effects of
smoke and avoid the highly addictive properties of tobacco.
Secondly, they say that in countries where cannabis is
legalized, the potency of cannabis could potentially be addressed. In parts of
the USA where cannabis is legalized, THC is not regulated and extremely potent
cannabis products (up to 75% THC) have gained popularity.
Some policy makers in
the Netherlands and Uruguay have suggested introducing a cap to limit THC
content to 15% and more evidence is needed on the effect of these measures.
Alternative options might include taxing cannabis according to THC content.
However, the authors argue that these strategies might not be
entirely successful, as cannabis users tend to prefer cannabis with a relatively
high THC content.
Instead, they argue that increasing the levels of CBD could
reduce some of the harmful effects of cannabis, without compromising the
effects users seek.
More research into the harms posed by different levels of
THC and CBD content is needed, and this information could potentially
contribute to guidelines on safer cannabis use, similar to alcohol.
"Although most users will not develop problems from their
cannabis use, it is vital, especially now that cannabis is becoming
increasingly liberalised, that we explore alternative and innovative ways by
which we can reduce and mitigate cannabis related harms" says Dr Amir
Englund, lead author from King's College London.
"With the rapidly
changing political climate around cannabis, the demand to effectively reduce
cannabis-related harms has never been greater, and more research is urgently
needed to inform policy decisions. A strategy based on increasing the content
of CBD in cannabis might be especially promising because CBD can offset several
harms associated with cannabis without compromising its rewarding
effects."
Dr Tom Freeman, a co-author and Senior Research Fellow for the
Society for the Study of Addiction said: "In the last eight years, the
number of people in the UK entering specialist treatment for cannabis increased
by over 50%. During the same time period, street cannabis has become
increasingly strong with high levels of THC and little or no CBD.
"Further
research on CBD is now needed -- both to investigate its potential role in mitigating
the harmful effects of THC in cannabis, but also as a potential treatment for
the minority of people who develop problematic cannabis use. Efforts to reduce
the common practice of mixing cannabis with tobacco could potentially prevent
people progressing to nicotine dependence, providing a substantial benefit for
public health."
