Cannabis - a Warning Against its Use in Multiple Sclerosis


There follows an article by Dr Thomas Stuttaford, published in The Times, 19th November 1998


In 1839, W B O’Shaughnessy, a professor of medicine at the University of Calcutta, introduced cannabis into Western medicine.  For the past 160 years, until recently, it has been doctors rather than schoolmasters who have had the greater professional interest in the drug. Mixtures derived from cannabis were regularly prescribed until the 1930s and 1940s for a variety of ills.  Queen Victoria and her doctor were firm advocates of a cannabis tincture to treat her period pains.


This week Estelle Morris, the School Standards Minister, took the discussion away from a world of white coats to one of mortar boards.  In fact, her remarks were not too revolutionary.  She was not advocating any laxity in the approach to the misuse of cannabis, merely more flexibility in the punishment system.


Increased acceptance of the medicinal benefits of cannabis, taken in the form of cannabinoid extracts, has tended to obscure the adverse reactions of cannabis smoking.  A few years ago voguish doctors were apt to overrule parental and even educational anxieties and encouraged the cannabis-smoking young person to continue.  They explained that they could see little difference between the parent having a gin and tonic or half a bottle of wine with dinner and the teenager puffing a joint.


Professor Wayne Hall, in association with Dr Nadia Solowij from the University of New South Wales, has recently reviewed the less desirable effects of Cannabis in The Lancet.


Most cannabis users stop in their mid to late twenties; few smoke it for more than a few years.  In the US and Australia only 10% become daily users of cannabis, although 20 to 30 per cent use the drug weekly.  Daily cannabis smokers are more likely to be men and tend to be less well educated.  They also take tobacco and alcohol regularly as well as a wide variety of other drugs.


Cannabis may induce anxiety and panic in those unused to it.  It reduces concentration, impairs memory and muscular coordination in the long and short term.  This is the price that has to be paid for the euphoria and the intensification of ordinary sensory experiences.  The effects on memory and concentration of persistent cannabis use are very subtle.  It is not known whether they are reversible after prolonged abstinence but, say the authors, they do create a cannabis-dependent syndrome so that regular users find it extremely difficult to give it up. The acute ill-effects include a liability to accidents, particularly when, as is often the case, the cannabis is combined with other drugs or alcohol.


The capacity of cannabis to increase the risk of psychotic symptoms should, in many doctors’ opinion, be enough to discourage its use.  It is unlikely that cannabis smoking may “cause” an acute psychotic breakdown but the overwhelming evidence is that it can induce this in those who, because of their lifestyle or their heredity, will be prone to schizophrenia and its related conditions.  The temperament and interests of those who may be in danger of developing mental illness may also draw them to cannabis smoking circles.  The continued use of cannabis may not be as obviously mentally destructive as that caused by long-term excessive drinking but the longer the patient has been smoking pot the greater the impairment.  This damage not only affects the person’s overall intellectual ability but the subtler aspects of reasoning and decision-making.


Cannabis smokers should realise the physical diseases induced by smoking.  They develop chronic bronchitis, just as tobacco smokers do, and their lungs show the changes that are precursors of malignant disease.  There may be an increased risk of cancers of the mouth , pharynx and gullet, and there is evidence that leukaemia is more common among babies borne to mothers who smoke cannabis when pregnant.


Professor Hall and Dr Solowij are adamant that those who should avoid cannabis are disturbed adolescents with poor school performance, people with a family history of schizophrenia and its related diseases, patients with asthma, bronchitis, emphysema, those who have already shown a tendency to over-indulge in alcohol or other drugs and, of course, pregnant women.


                                                                                            The Times: 19 Nov. 1998




The Cannabis Timebomb  by James Chapman, Science Correspondent. (Article published in the Daily Mail, July 2nd, 2003).


Shock Report reveals drug use increases risk of Mental Illness!


Cannabis users are seven times more likely to develop mental illness, a devastating report revealed last night.


Scientists said the drug affects the brain so seriously it is already one of the leading causes of psychosis in the UK.  Now there are fears that its widespread use among youngsters could result in an epidemic of schizophrenia.


The study was produced by Professor Robin Murray, head of psychiatry at the Institute of Psychiatry in London and one of the world’s leading authorities on mental illness.  He warned: “The link is now clear.  Its something society needs to think about very carefully.”


The findings will heighten concern about David Blunkett’s decision to reclassify cannabis from next year as a Class C drug like tranquillisers.  People caught with small amounts will be unlikely to be prosecuted.


Medical experts accuse the Home Secretary of leading young people to believe, wrongly, that it is harmless.


Cannabis is already the most widely used drug in the UK, after alcohol and cigarettes.  Official figures show a third of all 15-year-old have already tried it.


But Professor Murray warned: “The more cannabis that’s consumed, the more psychiatrists we are going to need.”  He told the annual meeting of the Royal College of Psychiatrists, in Edinburgh, that 80% of the patients he assessed with their first episode of psychosis had been using cannabis.


The rapid growth of the problem reflects the greatly increased strength of modern cannabis compared to that used by some parents of today’s teenagers, who often use their own experience to back claims that it is harmless.


Professor Murray said modern varieties contain up to ten times as much of the crucial ingredient, tetrahydrocannabinol (THC), which induces the “high”.  THC does this by affecting chemicals in the brain that transmit information from one nerve cell to another.


But its disruption of the delicate chemical balance may result in memory loss, anxiety and other conditions.  Long-term changes in the brain can lead to schizophrenia and psychosis.


Professor Murray said his results showed a strong correlation between sustained use of cannabis and psychotic episodes.


He pointed to earlier studies in Holland, Israel, Scotland and New Zealand which found that people who were taking more cannabis as teenagers and young adults were more likely to suffer mental illness in later years.


One study of 50,000 18-year-old Swedish army conscripts revealed that those who admitted taking cannabis on more than 50 occasions were six times more likely to develop schizophrenia in the following 15 years.


“These findings were largely ignored, “ Professor Murray told the conference.


“However, a number of studies have now confirmed that cannabis consumption act to increase later risk of schizophrenia.  This research must not be ignored.”


A Dutch study of some 4000 people showed that heavy users – those smoking two or more cannabis `joints’ a week – were almost seven times more likely to have psychotic symptoms three years later.


Dr Helen Verdoux, of the University of Bordeaux in France, told the conference her research suggested that people with a family history of psychiatric illness were particularly vulnerable.  Smoking two `joints’ a week was enough to trigger psychosis in this group.


In Britain, about eight million people admit to having smoked cannabis.


As well as mental illness the drug can cause cancer and lung disease, and expertsd estimate it is now responsible for 30,000 deaths a year in the UK.


Yet the Home Office has justified moves to reclassify cannabis by saying they reflect the real difference in the health dangers of so-called `soft’ drugs as opposed to `hard’ drugs like heroin.


Marjorie Wallace, chief executive of the mental health charity Sane, said last night: “Professor Murray’s review confirms what we have feared for years.”


“For some people it is clear that it is a very dangerous substance.  There’s no way of knowing whether you have a vulnerability to mental illness or psychosis, so smoking cannabis is a bit like playing Russian roulette.”


She said the research cast doubt on the wisdom of the decision to downgrade cannabis from Class B.  “If the Government is set on this course, it must go together with a major education campaign in schools so children are properly warned about the danger cannabis poses to mental health.


Another recent study suggested that cannabis can damage everyday memory such as putting names to faces or remembering to pick up car keys.


People who smoked the drug between five and twenty times a month were found to have ten per cent more of these memory problems than non-users, while those who smoked it more than twenty times had twenty per cent more.


Earlier this year, the United Nations drugs watchdog warned that the Government’s `softly softly’ approach on cannabis was putting the health of a generation in peril.


The International Narcotics Control Board said the downgrading decision had caused confusion and misunderstanding.  It said that research suggested that nine out of ten children believed the drug was now legal in Britain.


Mr Blunkett’s decision has also been roundly condemned by experts who say that cannabis is a stepping stone to harder drugs.


Summary and Comment by Dr M R Lawrence:


Many people with MS have chosen to use this drug, either by smoking it or by ingestion, for the purpose of relieving symptoms of pain or muscle spasm.  Considering the related symptoms of cannabis use, listed above, it may be suggested that this practice is, at least, unwise, and possibly even dangerous!


It is known that MS patients who smoke tobacco suffer a transient muscle weakness, which lasts for about fifteen minutes after each cigarette.  This is expectedly due to the rapid effect of nicotine which results in vasoconstriction (narrowing of the small blood vessels) in the body and brain. 


This can only add to the effects of the disease itself, thus, in the long-term, increasing the symptoms suffered and the level of disability established.


It is also known that cannabis smokers inhale more deeply and tend to hold the smoke for longer within their lungs.  This behaviour probably accounts for the greatly increased incidence of lung cancer in cannabis smokers.  The risk is increased by about 20 times compared with ordinary tobacco smokers.


It is also known that the risk of cancer in ordinary smokers is already increased by about twenty times compared with non-smokers.  Thus, the overall risk of cancer in a cannabis smoker is about 400 times that of a non-smoker.


The risk of lung and other cancers may be increased even more for MS sufferers as it is known that such patients often have a marked disruption of the immune system which could make them far more susceptible to infectious diseases and to such as cancer.


In addition, it has been discovered that long-term cannabis smokers may suffer a dramatic and obvious form of premature brain atrophy (brain shrinkage).  This has become apparent by brain-scan studies of the brains of habitual cannabis-users.


It therefore seems grossly inappropriate that we should treat one established form of brain damage, (the MS), with a method that results in even more extensive and permanent brain damage, due to the cannabis. 


In comparison, the damage due to the MS may be considered largely repairable, as can be seen in those suffering an acute relapse, after which the recovery process will often restore 90% or more of the function lost.


Even more long-term damage, due to established disease, may soon be repairable using current research projects including implants or infusions of stem-cells, or drugs such as neuro-immunophylins.


In this context therefore, the recent support for Sativex, a cannabis-based drug, by the MS Society seems grossly ill-advised and obviously unsuitable as a therapy for MS.


Please address any questions or other comments to Dr Bob Lawrence, at either the e-mail address, bob.lawrence@ntlworld.com, or the address below.