What is cannabis?
Cannabis sativa and cannabis
indica are
members of the nettle family that have grown wild
throughout the world for centuries. Both plants have
been used for a variety of purposes including hemp
to make rope and textiles, as a medical herb and as
the popular recreational drug.
The plant is used as:
-
The resin – a brown/black
lump, known as bhang, ganja, hashish, resin
etc;
-
Herbal cannabis – made up of
the dried flowering tops and variable amounts of
dried leaves - known as grass, marijuana, spliff,
weed etc.
Skunk refers
to a range of stronger types of cannabis, grown for
their higher concentration of active substances. The
name refers to the pungent smell they give off while
growing. They can be grown either under grow-lights
or in a greenhouse, often using hydroponic (growing
in nutrient rich liquids rather than soil)
techniques. There are hundreds of other varieties of
cannabis with exotic names such as AK-47 or
Destroyer.
Street cannabis can come in a wide variety of
strengths, so it is often not possible to judge
exactly what is being used in any one particular
session.
How is it used?
Most commonly, the resin or the dried leaves are
mixed with tobacco and smoked as a ‘spliff’ or
‘joint’. The smoke is inhaled strongly and held in
the lungs for a number of seconds. It can also be
smoked in a pipe, a water pipe, or collected in a
container before inhaling it - a 'bucket'. It can be
brewed as tea or cooked in cakes.
More than half of its psychologically active
chemical ingredients are absorbed into the blood
when smoked. These compounds tend to build up in
fatty tissues throughout the body, so it takes a
long time to be excreted in the urine. This is why
cannabis can be detected in urine up to 56 days
after it has last been used.
What is its legal status in the UK?
Cannabis was re-classified in January 2009 and is
now a Class B drug under the Misuse of Drugs Act,
1971.
The maximum penalties are:
-
For possession: 5 years
prison sentence or an unlimited fine, or both
-
For dealing/supplying:14 year
prison sentence or an unlimited fine, or both.
Young people in possession of cannabis
A young person found to be in possession of cannabis
will be:
-
Arrested
-
Taken to a police station
-
Given a reprimand, final
warning or charge, depending on the offence.
After one reprimand, a further offence will lead to
a final warning or charge.
After a final warning:
Adults in possession of cannabis
This will usually result in a warning and
confiscation of the drug. Some cases may lead to
arrest and either caution or prosecution, including:
How does it work and what is the chemical
make-up of cannabis?
There are about 400 chemical compounds in an average
cannabis plant. The four main compounds are called
delta-9-tetrahydrocannabinol (delta-9-THC),
cannabidiol, delta-8-tetrahydrocannabinol and
cannabinol. Apart from cannabidiol (CBD), these
compounds are psychoactive, the strongest one being
delta-9-tetrahydrocannabinol. The stronger varieties
of the plant contain little cannabidiol (CBD),
whilst the delta-9-THC content is a lot higher.
When cannabis is smoked, its compounds rapidly enter
the bloodstream and are transported directly to the
brain and other parts of the body. The feeling of
being ‘stoned’ or ‘high’ is caused mainly by the
delta-9-THC binding to cannabinoid receptors in the
brain. A receptor is a site on a brain cell where
certain substances can stick or “bind” for a while.
If this happens, it has an effect on the cell and
the nerve impulses it produces. Curiously, there are
also cannabis-like substances produced naturally by
the brain itself – these are called endocannabinoids.
Most of these receptors are found in the parts of
the brain that influence pleasure, memory, thought,
concentration, sensory and time perception. Cannabis
compounds can also affect the eyes, the ears, the
skin and the stomach.
What are its effects?
Pleasant
A ‘high’ - a sense of relaxation, happiness,
sleepiness, colours appear more intense, music
sounds better.
Unpleasant
Around 1 in 10 cannabis users have unpleasant
experiences, including confusion, hallucinations,
anxiety and paranoia. The same person may have
either pleasant or unpleasant effects depending on
their mood and circumstances. These feelings are
usually only temporary – although as the drug can
stay in the system for some weeks, the effect can be
more long-lasting than users realise. Long-term use
can have a depressant effect, reducing motivation.
Education and learning
There have also been suggestions that cannabis may
interfere with a person's capacity to:
-
concentrate
-
organise information
-
use information
This effect seems to last several weeks after use,
which can cause particular problems for students.
However, a large study in New Zealand followed up
1265 children for 25 years. It found that cannabis
use in adolescence was linked to poor school
performance, but that there was no direct connection
between the two. It looked as though it was simply
because cannabis use encouraged a way of life that
didn't help with schoolwork.
Work
It seems to have a similar effect on people at
work. There is no evidence that cannabis causes
specific health hazards. But users are more likely
to leave work without permission, spend work time on
personal matters or simply daydream. Cannabis users
themselves report that drug use has interfered
with their work and social life.
Of course, some areas of work are more demanding
than others. A review of the research on the effect
of cannabis on pilots revealed that those who had
used cannabis made far more mistakes, both major and
minor, than when they had not smoked cannabis. As
you can imagine, the pilots were tested in flight
simulators, not actually flying... The worst effects
were in the first four hours, although they
persisted for at least 24 hours, even when the pilot
had no sense at all of being 'high'. It concluded
"Most of us, with this evidence, would not want to
fly with a pilot who had smoked cannabis within the
last day or so".
What about driving?
In New Zealand, researchers found that those who
smoked regularly, and had smoked before driving,
were more likely to be injured in a car crash. A
recent study in France looked at over 10,000 drivers
who were involved in fatal car crashes. Even when
the influence of alcohol was taken into account,
cannabis users were more than twice as likely to be
the cause of a fatal crash than to be one of the
victims. So - perhaps most of us would also not want
to be driven by somebody who had smoked cannabis in
the last day or so.
Mental health problems
There is growing evidence that people with serious
mental illness, including depression and psychosis,
are more likely to use cannabis or have used it for
long periods of time in the past. Regular use of
the drug has appeared to double the risk of
developing a psychotic episode or long-term
schizophrenia. However, does cannabis cause
depression and schizophrenia or do people with these
disorders use it as a medication?
Over the past few years, research has strongly
suggested that there is a clear link between early
cannabis use and later mental health problems in
those with a genetic vulnerability - and that there
is a particular issue with the use of cannabis by
adolescents.
A study following 1600 Australian school-children,
aged 14 to 15 for seven years, found that while
children who use cannabis regularly have a
significantly higher risk of depression, the
opposite was not the case - children who already
suffered from depression were not more likely than
anyone else to use cannabis. However, adolescents
who used cannabis daily were five times more likely
to develop depression and anxiety in later life.
Three major studies followed large numbers of people
over several years, and showed that those people who
use cannabis have a higher than average risk of
developing schizophrenia. If you start smoking it
before the age of 15, you are 4 times more likely to
develop a psychotic disorder by the time you are 26.
They found no evidence of self-medication. It seemed
that, the more cannabis someone used, the more
likely they were to develop symptoms.
Why should teenagers be particularly vulnerable to
the use of cannabis? No one knows for certain, but
it may be something to do with brain development.
The brain is still developing in the teenage years –
up to the age of around 20, in fact. A massive
process of ‘neural pruning’ is going on. This is
rather like streamlining a tangled jumble of
circuits so they can work more effectively. Any
experience, or substance, that affects this process
has the potential to produce long-term psychological
effects.
Recent research in Europe, and in the UK, has
suggested that people who have a family background
of mental illness – and so probably have a genetic
vulnerability anyway - are more likely to develop
schizophrenia if they use cannabis as well.
Physical health problems
The main risk to physical health from cannabis is
probably from the tobacco that is is often smoked
with.
Is there such a thing as ‘cannabis
psychosis’?
Recent research in Denmark suggests that yes, there
is. It is a short-lived psychotic disorder that
seems to be brought on by cannabis use but which
subsides fairly quickly once the individual has
stopped using it. It's quite unusual though – in the
whole of Denmark they found only around 100 new
cases per year.
However, they also found that:
So, it also seems probable that nearly half of those
diagnosed as having cannabis psychosis are actually
showing the first signs of a more long-lasting
psychotic disorder, such as schizophrenia. It may be
this group of people who are particularly vulnerable
to the effects of cannabis, and so should probably
avoid it in the future.
Is cannabis addictive?
It has some of the features of addictive drugs such
as:
These symptoms of withdrawal produce about the same
amount of discomfort as withdrawing from tobacco.
For regular, long-term users:
The irritability, anxiety and problems with sleeping
usually appear 10 hours after the last joint, and
peak at around one week after the last use of the
drug.
Compulsive use
The user feels they have to have it and spends much
of their life seeking, buying and using it. They
cannot stop even when other important parts of their
life (family, school, work) suffer.
You are most likely to become dependent on cannabis
if you use it every day.
What about skunk and other stronger
varieties?
The amount of the main psycho-active ingredient,
THC, that you get in herbal cannabis varies hugely
from as low as 1% up to 15%. The newer strains,
including skunk, can have up to 20%. The newer
varieties are, on the whole, two or three times
stronger than those that were available 30 years
ago. It works more quickly, and can produce
hallucinations with profound relaxation and elation
– along with nervousness, anxiety attacks,
projectile vomiting and a strong desire to eat. They
may be used by some as a substitute for Ecstasy or
LSD.
Legally, these strains remain classified Class B
drugs. While there is little research so far, it is
likely that these stronger strains carry a higher
risk of causing mental illness. A major study
currently underway, has already reported problems
with concentration and short-term memory in users of
stronger types of cannabis.
Problems with cannabis use
Many – perhaps most – people who use cannabis do
enjoy it. But it can become a problem for some
people. A US organisation, marijuana-anonymous.org,
defines the problems of cannabis as follows:
“If cannabis controls our lives and our thinking,
and if our desires centre around marijuana - scoring
it, dealing it, and finding ways to stay high so
that we lose interest in all else.”
The website carries the following questionnaire –
which could equally well apply to alcohol use.
"If you answer ‘Yes’ to any of the questions, you
may have a problem.
1. Has smoking pot stopped being fun?
2. Do you ever get high alone?
3. Is it hard for you to imagine a life without
marijuana?
4. Do you find that your friends are determined by
your marijuana use?
5. Do you smoke marijuana to avoid dealing with your
problems?
6. Do you smoke pot to cope with your feelings?
7. Does your marijuana use let you live in a
privately defined world?
8. Have you ever failed to keep promises you made
about cutting down or controlling your dope smoking?
9. Has marijuana caused problems with memory,
concentration, or motivation?
10. When your stash is nearly empty, do you feel
anxious or worried about how to get more?
11. Do you plan your life around your marijuana use?
12. Have friends or relatives ever complained that
your pot smoking is damaging your relationship with
them?”
Reducing cannabis use
The Home
Office recently
published a guide on how to cut down and stop
cannabis use. It suggests a range of things you can
do to successfully stop using, including:
-
drawing up a list of reasons
for wanting to change
-
planning how you will change
-
thinking about coping with
withdrawal symptoms
-
having a back-up plan.
If you decide to give up cannabis, it may be no more
difficult than giving up cigarettes. You could try:
Many people will be able to stop on their own.
However, if this isn't enough:
-
Join a support group, for
instance the on-line Marijuana
Anonymous UK
-
Talk to your GP or practice
nurse. They will have a lot of experience in
helping people to cut down their drinking and to
stop smoking. They can also refer you to more
specialist services, such as a counsellor,
support group NHS substance misuse service.
-
NHS substance misuse services
offer assessment and counselling for a range of
street drugs, aiming to help with
-
harm reduction – reducing
the impact of the drug on your life
-
abstinence – stopping
completely
-
relapse prevention – not
starting to use again
-
some offer a specific
service for cannabis users.
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