literature made available by foresight go to the Foresight home page
view more booklets / leaflets / articles
print this page
go back to the previous page

CANNABIS - THE FACTS (ARTICLE)
The following article was kindly presented by Mary Brett, Former Head of Health Education, Dr Challoner's Grammar School (boys), Amersham, Bucks. UK spokesman for EURAD (Europe Against Drugs).

100 billion nerve cells (neurons) may have up to 10,000 connections to other neurons in the vast brain network. Messages pass along the nerve fibres as electrical impulses, then cross the gap between the neurons (the synapse) in the form of chemicals – neurotransmitters – the brain’s natural drugs. Each neurotransmitter molecule has a particular shape to fit into its receptor site on the next neuron as a key fits into a lock.
Mind-altering drugs like cannabis or more specifically THC (tetrahydrocannabinol), the ingredient that gives the “high”, mimic the shape of these neurotransmitters so the brain is “fooled”. Cannabis mimics anandamide and also interferes with the transmission of the other neurotransmitters because THC dissolves in the fatty cell membranes and persists. Fifty per cent of the THC is still there after a week and ten per cent a month later. Traces are still detectable in hair and urine for weeks after that.
 


The Immediate effects

Taken for euphoria, usually smoked with or without tobacco, or eaten in “hash” cakes. (But enhances the mood you’re in so you may well feel worse).

An intoxicant, like alcohol, so people should not be driving. If you have a joint today you should not be driving tomorrow. (Airline pilots on flight simulators could not ‘land’ their planes properly even 24 hours and more after a joint and had no idea anything was wrong.)

One 20mg joint has the same effect as being just over the legal alcohol-driving limit. The combination of cannabis and alcohol is 16 times more dangerous when driving than taking either drug alone.

Panic attacks and paranoia can occur immediately after a joint.

The long-term effects.

Just one joint per week or even once a month will ensure a permanent presence of THC. Since the other neurotransmitters are affected, new nerve connections cannot be made properly. Concentration, learning and memory are all badly affected. School grades fall, some students miss out on university places. A cannabis personality develops. Users become inflexible, can’t plan their days properly, can’t take criticism and struggle to express themselves. They feel lonely, miserable and misunderstood. Apathy, amotivation and dropping out are all common.

Few children, using cannabis even occasionally, will achieve their full potential.

Dependence.

Psychological addiction, the craving for cannabis is very strong.
Physical addiction occurs. As more and more THC is consumed, more receptor sites are made, tolerance builds as more THC is needed to get the same effect. All the receptor sites need to be satisfied, this is physical addiction. Withdrawal symptoms are not so dramatic as they are for heroin as THC persists in the body. More young people now are treated in the USA for marijuana than alcohol dependence.
There is no foolproof cure for any type of addiction.

Mental Health.

Cannabis psychosis has been reported in scientific papers for decades. Cannabis causes far more mental illness than drugs like heroin.

The increased risk factors for psychosis, anxiety, and depression range from 3 to 5. Schizophrenia is triggered or worsened by its use, it may even be caused. Cannabis increases the amount of the neurotransmitter dopamine in the brain. Schizophrenics have an excess of dopamine in the brain, sufferers of Parkinson’s disease, too little.
(One in four of us carries a faulty gene which controls the release of dopamine. If a child inherits a copy of the gene from each parent, and if they then use cannabis, the chance that she/he will develop schizophrenia rises from 1 or 2%, the norm in the population, to 15%). The presence of one gene increases the risk by 5 to 6 times.

Violence and Suicide A Swedish study found more suicides among pot users than those who used alcohol, amphetamines or heroin. The manner of death was more violent.
A study in 2001 from Dunedin found that young male cannabis users were nearly five times more likely to be violent than non users, the risk for alcohol users was around three. Violence seems to occur with the psychosis or during withdrawal.

Other Effects on the body

Cannabis contains more cancer-causing substances than tobacco, its smoke deposits three to four times as much tar in the lungs and airways. Cases of lung cancer, bronchitis and emphysema have been reported.

Rare head and neck cancers are now being found in young pot smokers. The average age for these conditions in tobacco smokers is 64.

The immune system is damaged. Fewer white blood cells are produced, many are abnormal and can't fight off infections. People are more vulnerable to disease, their illness is more severe and they stay sick longer.

Sperm production is decreased. Infertility and even impotence have been reported.

Babies born to cannabis using mothers are smaller, hyperactive, have behaviour and learning problems and are 10 times more likely to develop leukaemia.

THC interferes with the production of new cells being made in an adult body - white blood cells, sperm and foetal cells. (It causes faulty copying of DNA, and hastens cell death.)

Blood pressure and heart rates rise to the levels of real stress. Heart attacks have been reported. Two teenagers had strokes and died after bingeing on cannabis, another was left paralysed.

The Medical Argument

Medicines by law, have to be pure substances, single chemicals, so that their actions are predictable and controllable. Heroin and cocaine fall into that category. Cannabis contains around 400 chemicals.
The BMA is currently testing more of the 60 or so purified cannabinoids (substances unique to the cannabis plant) as potential medicines and that is correct procedure.
Synthetic purified THC, Nabilone, (Marinol in USA) is already available on hospital prescription but has many side-effects and is not popular among doctors.

It all started in 1979 when an American pot smoking lawyer said, "We will use the medical marijuana argument as a red herring on the road to full legalisation".

The Pro-legalisers.

Many pro-legalisers are users, or their children are.
Others are libertarians who think we should be able to do what we like with our bodies. That’s fine as long as it doesn’t interfere with anyone else. But stoned drivers can and do kill other people. Addicts and the mentally-ill need treatment at the taxpayers expense, stoned workers are inefficient and unproductive.
And passive smoking does occur.

Cannabis as a gateway drug?

Tobacco, alcohol and cannabis can all act as gateway drugs. A recent New Zealand study showed that weekly cannabis users were 60 times more likely to progress to “harder” drugs. The more they use, the greater the risk. Almost 100% of heroin users started on pot. New research suggests that cannabis can “prime” the brain for the use of other drugs.

Relaxing the law

Holland turned a blind eye to cannabis in 1987 and is now the crime capital of Europe. The country is awash with dealers, and it is a major producer and exporter of drugs especially ecstasy.
Health and social problems have escalated and the amount allowed for personal possession has been reduced from 30g to 5g. The present Dutch government wants to close all the coffee shops. Many have gone.

Since down-classification in 2001 in the UK, regular cannabis use is still rising among 11 to 12 year old boys, older teens seem to have progressed to cocaine.

Strength

In the sixties and seventies, the average THC content of herbal cannabis was just 0.5 - 1%.
Today’s specially bred varieties from Holland such as skunk and nederweed, have THC contents of anything from 9-27%. These strong types are now commonly grown in the UK and are thought to account for 60% of the cannabis consumed here.
The rest of the cannabis used here is cannabis resin with a THC content of around 4 to 5%.

Drug Testing

More and more employers are testing for drugs in the workplace – cannabis will show up for weeks, and a conviction would prevent someone from getting a visa for the USA.

Quotations from the Experts:

Mental illness: “Five years ago, 95% of psychiatrists would have said that cannabis doesn’t cause psychosis. Now I would estimate that 95% say it does”
(Professor Robin Murray, Director Institute of Psychiatry, London. October 2006).

“The mistake was that in its 2002 report, The Advisory Council on the Misuse of Drugs denied that cannabis was a contributory cause of schizophrenia, continued to deny this for the next two years and thus mislead ministers into repeatedly stating that there was no causal link between cannabis and psychosis”.
( Professor Robin Murray, letter to The Guardian, 19/01/06).

Personality: “If the development of identity does not progress, the teenager remains at a childish level of development characterised by both a lack of independence and a deficient integration in the adult world”. (Swedish researcher, Jan Ranstrom 2003)

Academic performance: “Use more often than twice per week for even a short period of time, or use for 5 years or more at the level of even once per month, may each lead to a compromised ability to function to their full mental capacity, and could possibly result in lasting impairments”
(Dr Nadia Solowij, “Cannabis and Cognitive Functioning” 1998).

Medical argument: Dr Keith Green an American ophthalmologist, says 6 joints a day would be needed to maintain reduced eye pressure caused by glaucoma, rendering the patient incapable of any useful functioning.

The warning on Nabilone reads: “THC encourages both physical and psychological dependence and is highly abusable. It causes mood changes, loss of memory, psychoses, impairment of coordination and perception, and complicates pregnancy”.

Dr Robert Dupont, founder of NIDA (National Institute for Drug Abuse) in the USA said, “I have been apologising to the American people for the last 10 years for promoting the decriminalisation of cannabis. I made a mistake. Marijuana combines the worst effects of alcohol and tobacco and has other ill effects that neither of these two have”.

He added, “In all of history, no young people have ever taken marijuana regularly on a mass scale. Therefore our youngsters are in effect making themselves guinea pigs in a tragic experiment. Thus far our research clearly suggests we will see horrendous results”

References can be found in “Cannabis – a general view of its harmful effects” by Mary Brett on the “Talking about Cannabis” website. June 2007.

More:- Foresight Literature Summaries

Copyright © 2006 Foresight Association For The Promotion Of Pre-Conceptual Care Registered Charity No: 279160. All Rights Reserved