Cannabis and MS - A Warning

It is known that Muliple Sclerosis patients who smoke tobacco suffer a transient muscle weakness which lasts for about fifteen minutes after each cigarette. This is likely 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 increasing, in the long-term, 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 greater than for ordinary tobacco smokers.

The risk of cancer in ordinary smokers is 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 patients 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 seems therefore grossly inappropriate that we should treat one established form of brain damage, due to the MS, with a method, which 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 brain cell implants or drugs such as neuro-immunophylins.

However current research is showing the Sativex is proving effective in reducing pain, muscle spasms and bladder problems in people with MS.

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.

© Multiple Sclerosis Resource Centre