2. Cannabis in Switzerland: The current situation
Cannabis may be used legally as a renewable raw material in the textile, oil, paper, rope and construction industries and in the production of foodstuffs and consumer goods; it is also consumed illegally as a narcotic (marijuana, hashish, hash oil). There has been a sharp increase in cannabis cultivation in Switzerland recently, with the resulting products destined not only for the legal market but also, and more particularly, for illicit consumption as narcotics (" drug- grade cannabis").
| Year | 1993 | 1994 | 1995 | 1996 | 1997 | 1998 |
| a) Renewable raw material¹ | 0 | 10 | 11 | 6 | 2 | 60 |
| b) Other uses² | 1 | 10 | 50 | 150 | 200 | ~250 |
Table 1: Area under cannabis cultivation (ha) in Switzerland and uses
¹ Figures from the Federal Office of Agriculture (BLW)
² Estimate from BLW documentation
The drug grade has a THC * content in excess of 0.3 percent (see 2.3); the industrial or fiber grade contains less than 0.3 percent THC. Since even experts cannot distinguish "industrial cannabis" from "drug cannabis" with the naked eye, it is not possible to tell what type of cannabis is being cultivated unless the plants are analyzed chemically. The figures for b) in the above table have therefore been classified as "other uses" even though it has to be assumed that these crops are used predominantly to produce "drug cannabis".
*THC: The active principle is tetrahydrocannabinol (cf. Chapter 2.3). In this report only the abbreviation THC will be used (except in Chapters 2.3 and 2.5).
2.2.1.1 Cannabis in agriculture
The cannabis plant is well adapted to the geography, soil and climate in Switzerland. It makes few demands on the soil and can generally be grown without the aid of chemical crop protection agents. As such it is an ideal candidate for integrated production (IP) and ecological cultivation. From an agronomic point of view, the prospects for the successful reintroduction of industrial cannabis production are excellent. There is major public interest in ecological products derived from sustainable resources. Cannabis is a promising plant which is easy to grow and provides a high quality raw material. This is why the "renewable raw materials" project being run by the Federal Office of Agriculture (BWL) is funding the cultivation of low- THC cannabis (containing less than 0.3 percent THC) for industrial purposes.
Switzerland has had a type list 1 covering the marketing of cannabis seed for agricultural purposes since 1 March 1998. This list restricts trade in cannabis seeds and plants to varieties containing low levels of THC. The cultivation of cannabis and activities outside the agricultural context (e. g. ornamental plants) are not covered by this regulation.
2.2.1.2 Cannabis for food products, cosmetics and consumer goods
The flowers, seeds, fatty and volatile l oils, and other parts of the hemp plant are currently used to manufacture foodstuffs and cosmetics. A variety of products including hemp oil, biscuits, chocolate, confectionery, pasta, "beer flavored with hemp blossom", and a number of skin and hair care products can be purchased. Food products and cosmetics containing hemp are not permitted to have any pharmacological activity. The revision of the Ordinance on Foreign Substances and Ingredients in Food Products (FIV) dated 30 January 1998 established threshold values for the THC content of various foods 2 . By analogy with the FIV, a limit of 50 mg/ kg is applied to cosmetic products which are left on the skin. The situation in the food and cosmetics sector has eased considerably since these threshold values were introduced. Most of these cannabis products are sold in so- called hemp shops (in 1998 there were around 135 such shops in Switzerland). However, hemp shops sell not only legal products but also illicit cannabis products (cf. 2.2.2 Illegal use and 2.7 Enforcement of the existing legislation).
2.2.1.3 Medical use of cannabis
Chapter 2.5 deals specifically with the therapeutic use of the pharmacological effects of cannabis, or THC, in medicine.
The cultivation of drug- grade hemp and the associated sales of products made from this hemp are increasing from year to year in Switzerland. Relevant data from a number of cantons show that a large quantity of products based on drug- grade hemp are already being exported, and that an increasing volume of equipment and other items used in hemp cultivation and to produce marijuana and hashish are being imported into Switzerland. It can be assumed on the basis of a survey covering all cantons that most of the illegal trade in hashish is still carried out on the street, as it always has been. "Hemp shops", on the other hand, are increasingly the channel through which marijuana is sold; most of it is packed into and sold in the form of "aromatic pillows". In Ticino canton practically the entire cannabis market has gravitated towards "hemp shops". The police view is that the vast majority of hemp fields in Switzerland are used to produce cannabis supplied to the drug trade. It can be assumed that in 1998 considerably more than 100 metric tons of drug- grade cannabis were harvested. Today Switzerland has an almost nationwide network of 135 hemp shops. The big increase started in 1996 and led to the creation of major centers in the city and canton of Zurich (a total of 36), in the canton of St. Gallen (18), in Ticino (16) in Basel (7) and in the canton of Berne (6). Police information shows that between 85 and 95 percent of sales in most hemp shops come from drug products (" hemp pillows", "aromatic bags", "refills for aromatic bags", "hemp coins" etc.) The THC content of cannabis sold in "aromatic bags" is frequently between 8 and 10 percent, for example. The people who sell hemp products (in hemp shops) claim that their products (such as "aromatic pillows") are not intended for making drugs, and that it is therefore legal to sell them. It is up to the public prosecution agency to gather additional evidence and prove that the cultivation of hemp or the product in question is intended for making illegal narcotic substances or for consumption as an illegal drug. Chapter 2.7 deals with the difficulties faced by the prosecution authorities in distinguishing between legal and illegal use when inspecting areas used to cultivate cannabis and hemp shops.
1 Ordinance on the Production and Marketing of Seeds and Plants, as revised on 25 February 1998, and Ordinance of the Federal Office of Agriculture on the Varieties Catalog for Cannabis, 26 February 1998.
2 A limit of 50 mg THC/ kg applies to oils for culinary use; the maximum content in pasta, biscuits and cereal bars is 5 mg THC/ kg dry mass, and in beverages (including teas) 0.2 mg THC/ kg.
The cultivation of hemp for consumption has reached industrial proportions in Switzerland in the last few years. In 1997, 7.2 metric tons of hemp products and 313,258 hemp plants were impounded. Although reliable data are difficult to come by, it can be assumed that Switzerland has become a hemp- exporting country and is one of Europe's two major producers, the other being the Netherlands. Hemp is also being cultivated increasingly in private gardens and on balconies. This may be partly because hemp is an attractive ornamental plant; in many cases, however, this cannabis is no doubt intended for consumption. This report will not look at hemp cultivation in greater detail. The current situation and the related problems are described in the relevant documentation compiled during the amendment of the Swiss Narcotics Act, which was scheduled for distribution to the cantons for comment during the summer of 1999. Models which the Commission feels could be suitable for hemp cultivation are described in Chapters 3 and 6.
2.3. Pharmacology and toxicology of cannabis
Note on this chapter: In some places the following text goes into far more detail than the other chapters in this report. This exhaustive approach was taken deliberately, since an understanding of the complex effects of cannabis is vital for an objective discussion of the subject in hand, and very little summarizing literature is available on the aspects portrayed here. The reader not familiar with the biological terminology can omit the paragraphs printed in italics and smaller type without losing the essence of the text.
According to the current system of botanical classification, hemp belongs to the genus Cannabis which, together with the genus Humulus – hops, are included in the Family Cannabidaceae (Hagers Handbuch [...] 1992). Although the wide variety of characteristic features would suggest that there are several species of cannabis, today only one collective species is recognized, Cannabis sativa (Lehmann 1995). The other species commonly referred to, Cannabis indica – Indian hemp, is in fact a subspecies of Cannabis sativa (Fankhauser 1996). Cannabis sativa is a dioecious, green, leafy plant with characteristic opposite, usually sevenfingered, lance- shaped leaves; on dry, sandy, slightly alkaline soil it can grow to more than 7 meters in height. Glandular hairs develop, usually on the female flower, which secrete a resin. The greatest density of glandular hairs is found on the sepals and on the underside of the last leaves to form (Geschwinde 1996). The female plants are more important than the male plants for commercial purposes: their fibers are thicker, they form the nutritious seeds, and they contain the psychoactive principle tetrahydrocannabinol (THC) which is much sought after by producers of marijuana and hashish. Unlike most of the substances used in our western culture to induce an intoxication, cannabis is not a single substance but contains a large number of different components; over 420 have been identified to date. The cannabinoids, of which there are over 60, are the most important class containing the active principle responsible for the psychotropic effects of the plant, (-)- trans- 9 -tetrahydrocannabinol (referred to in the following as 9 -THC). Basically all the parts of the Cannabis sativa plant can contain cannabinoids, not just the seeds, but the quantity varies from one part to another. The resin secreted by the female glandular hairs contains up to 90 percent cannabinoids, the bracts of the flowers and fruits contain an average of 3 to 6 percent, and the leaves contain only 1 to 3 percent (Geschwinde 1996). The fiber grade of cannabis is cultivated for industrial purposes, and the legislation in the European countries requires this type to contain no more than 0.3 percent THC (see also 2.2.1). The most important cannabis products in the drug trade are marijuana and hashish. Marijuana consists of all the dried parts of the plant; it is sold either loose or pressed and contains up to 2 percent THC. The THC content is increased (up to 6 percent) by using only the flowering tops of the female plants. Hashish is a particularly resinous form of cannabis, and good quality hashish contains between 10 and 20 percent THC (Lehmann 1995). The THC content of cannabis plants can be increased by selective breeding and optimal growing conditions. The ”Sinsemilla” type of marijuana, for example, had a THC content of 1 percent in the 1960s, 8.5 percent in the early 1980s, and as much as 17 to 22 percent in the 1990s (Adams, Martin 1996; Geschwinde 1996).
2.3.2.1 Absorption, metabolism and excretion
Cannabis is usually smoked as a "joint", a variable mixture of hashish (or marijuana) and tobacco. The dosage depends on the desired effect (generally one cigarette containing 2 percent THC). The active principle is absorbed very rapidly via the respiratory tract and lungs, with an onset of action just a few minutes later. The effect peaks at 15 minutes, subsides gradually after 30 to 60 minutes, and is largely finished after 2 to 3 hours (Geschwinde 1996). The bioavailability (proportion of substance active in the body) depends greatly on the smoker's technique and varies between 10 and 25 percent (with a maximum of 56 percent). THC is absorbed by the body much more slowly after oral intake (eating or drinking) and then has a lower bioavailability of 4 to 12 percent because of the poorer absorption, catabolism in the liver and the fact that the inactive tetrahydrocannabinolidic acids in natural cannabis products cannot be transformed into psychoactive 9 -THC unless they are heated first, as is the case when they are smoked (Lehmann 1995). In contrast to absorption through the respiratory tract, in which peak plasma concentrations of THC may be achieved while the product is being smoked, the plasma concentration increases constantly over a period of 4 to 6 hours when cannabis is ingested; a state of intoxication is reached later and is of a different quality.
The high solubility of 9 -THC and its active metabolite 11- OH- 9 -THC in fat mean that they are bound almost completely to protein in the plasma, cross the blood- brain barrier with ease, and are eliminated only slowly from lipid- containing tissue. This slow elimination gives the substances a biological half- life of one day (Lehmann 1995); other authors have reported half- lives of three to five days (Adams, Martin 1996). The substances are thought to be metabolized twice as quickly by chronic users of cannabis as by first- time users (Adams, Martin 1996; Maykut 1985).
The relationship between plasma concentrations and the degree of intoxication is discussed in Chapter 2.3.5 (Cannabis and driving).
The cannabinoids are metabolized rapidly in the liver. To date, some 80 different, mostly inactive metabolites have been identified (Agurell et al 1986). No major metabolic differences between male and female users of cannabis have been observed (Wall et al 1983).
Specific research into the mode of action of cannabis was not possible until 1964 (Agurell et al 1986), when 9 -THC was isolated and its structure was elucidated. It then became possible to develop substances with an action similar to THC, some of them highly potent. During the 1980s, various scientific findings removed any lingering doubt about the existence of specific cannabis receptors (Bidaut- Russel et al 1990; Dewey et al 1984; Howlett, Fleming 1984; Howlett et al 1986).
A cannabinoid receptor (CB1) located predominantly in the cerebellum, the hippocampus and the cerebral cortex was finally discovered and cloned in 1990 (Axelrod, Felder, 1998). A further, peripheral, receptor (CB2) was found in certain parts of the immune system (e. g. the spleen) in 1993 (Abood, Martin, 1996; Lehmann, 1995). Investigations carried out to date would seem to confirm that these receptors are capable of affecting neurophysiological processes in the brain (Axelrod, Felder, 1998). Future research will reveal the extent to which processes of this type involving cannabinoid receptors are linked to the complex effects of cannabis in humans.
In 1992 the endogenous ligand (linking substance) anandamide was discovered; it is thought to be synthesized and released on an ad hoc basis (Abood, Martin 1996; Axelrod, Felder 1998; Di Marzo et al 1994).
The discovery of the cannabinoid receptors, endogenous ligands, and the development of specific agonists and antagonists in the past and the future, are making a major contribution to scientific understanding of the effects of cannabis, of the neurophysiological role played by thes receptors, and of the possible effects on the human brain and its functions in the context of chronic cannabis use. New knowledge will perhaps enable us to develop an active principle which is therapeutically highly active but has none of the psychoactive properties.
2.3.3 Acute effects of cannabis on the central nervous system
The psychotropic (affecting the central nervous system and the mind) action of cannabis is one of the reasons why cannabis products are used so widely. As mentioned above, cannabis starts to act more rapidly and more intensively when it is smoked, and the intoxication lasts a shorter time, than when it is absorbed through the digestive system. The effect of cannabis depends not only on its composition, dosage and mode of consumption; much also depends on the mood of the individual, on the individual's expectations and on the atmosphere and setting. These factors explain why the altered state of consciousness, which may amount to pronounced intoxication, is experienced so differently by different people. At a low to moderate dose, cannabis produces a largely pleasant feeling of relaxed euphoria, perhaps even with dreamy elements, which may be accompanied by heightening or alteration of the senses (Hagers Handbuch [...] 1992). The sense of time shifts markedly, and the individual perceives periods of time as being considerably longer than they really are. Short- term memory is impaired (Lehmann 1995), although recall of previously acquired knowledge is impaired only slightly if at all. It is uncertain whether other higher functions of the brain, such as the organization and integration of complex information, are affected (Adams, Martin 1996). Higher doses produce a general reduction in spontaneity, drive and involvement in the surroundings. Anxiety, confusion, aggressive feelings, (pseudo) hallucinations, nausea and vomiting have all been reported but are not usually experienced. They may, however, develop even in experienced users (Hagers Handbuch [...] 1992; Lehmann, 1995). As the effects of THC subside, the individual often becomes drowsy and tired, but there is no "hang- over" comparable to the effect experienced after heavy alcohol consumption.
2.3.4 Acute side effects and toxicity of cannabis
The physiological effects observed immediately after consumption are reddening of the conjunctivae, a reduction in body temperature, a dry mouth and throat, hunger, a slightly elevated heart rate and blood pressure when lying down, and a drop in heart rate and blood pressure when standing (Adams, Martin 1996; Dewey 1986; Hagers Handbuch [...] 1992). The acute toxicity of cannabis is generally thought to be low. If the dose of cannabis lethal in rhesus monkeys is extrapolated to man, a human would have to smoke 100 grams of hashish to achieve the same effect. No fatality has ever been reported in connection with acute cannabis intoxication either in Switzerland or elsewhere. Deaths overall are very rare following cannabis consumption, and are generally a consequence of the potentially increased inclination to suicide associated with an atypical course of intoxication (Hagers Handbuch [...] 1992). Use of high- dose cannabis products can lead to psychotic states which manifest as a combination of emotional symptoms, such as fluctuating mood, disorientation and schizophrenia- like states, and depression, anxiety, visual and auditory hallucinations and paranoid persecution mania. Panic reactions are often due to the individual's fear of losing control or his/ her mind. The treatment of such states often involves nothing more than reassuring the person. Drug therapy is generally unnecessary because the calming effect of the drug in any case comes to the fore as the intoxication subsides (Hagers Handbuch [...] 1992; Hollister 1986). When evaluating the significance of the potential negative effects of cannabis consumption mentioned above, it should not be forgotten that similar effects may also occur in patients using many of the psychoactive medications prescribed today.
Relationship between plasma concentration and degree of intoxication A number of studies have attempted to correlate plasma concentrations of 9 -THC and its metabolites with the psychoactive effects of cannabis in order to deduce the extent of the intoxicated state currently being experienced by an individual, or to determine when cannabis was last used. However, this is far more difficult than with alcohol because of the many factors that affect the pharmacological action of cannabis. Peak plasma concentrations do not correspond to the point of maximum intoxication when cannabis is inhaled (smoked), injected intravenously or ingested (eaten or drunk) (Cochetto et al, 1981). More recent mathematical models are thought to permit more accurate assessment of the time that has elapsed since cannabis was last consumed (WHO 1997).
Of particular interest in view of the widespread use of cannabis is its effect on the individual's ability to drive and operate machinery. Numerous studies of the effects of cannabis on psychomotor function and analysis of road traffic accidents following which THC and/ or alcohol have been detected in the plasma have produced inconsistent results. The most important aspect is how long cannabis is likely to affect the ability to drive after it has been taken. The reduced reaction speed and altered perception, alertness and ability to process information mean that cannabis is likely to impair the ability to drive as much as two to four hours after being smoked (up to a maximum of eight hours) (Adams, Martin 1996; Hollister 1986; Iten 1994; WHO 1997). It has been reported that cannabis users often overestimate the effect of cannabis on their ability to drive, and often drive slowly with great concentration, while individuals under the influence of alcohol tend to overestimate their driving skills (Adams, Martin 1996). However, it has also been noted that in 80 percent of road traffic accidents involving THC in the plasma alcohol had also been consumed (WHO 1997).
2.3.6 Medical uses of THC and cannabis
The therapeutic use of the pharmacological effects of cannabis and THC in medicine is the central theme of Chapter 2.5.
2.3.7 Effects of chronic cannabis use
Opinions differ, in some cases widely, on the effects of chronic cannabis use, and the results obtained from research to date leave room for assumptions and speculation. It appears to be practically impossible to demonstrate effects due solely to cannabis. It is difficult to extrapolate from animal experiments, some of which use high doses of pure substance and whose duration is too short to be comparable with chronic use of marijuana, to man. Even in clinical trials with chronic cannabis users, the results will be falsified for example, if the individuals studied have been consuming alcohol and tobacco for the same length of time. For this reason it is not possible to attribute the results solely to the use of cannabis with any degree of certainty. Moreover, the number of other possible causes of the effects observed grows as the duration of use gets longer (WHO 1997).
2.3.7.1 The Amotivational syndrome
Acute, reversible psychotic states have been documented in exceptional cases following cannabis use, but the existence of "the amotivational syndrome", first described in the literature in 1968, has never been confirmed. The term was used to describe the changes in attitude and personality, the neglect of appearance and general disinterest displayed by chronic users of cannabis, although nowadays it is considered to be obsolete and not typical of cannabis consumption (Huw 1993; WHO 1997). It is exceptionally difficult – if not impossible – to establish a direct and exclusive causality between speculative consequences of chronic cannabis use and the drug itself. For example, studies attempting to link dropping out of school at an early age with cannabis use have tended to show that it was in fact the family background, the child's relationship with its parents during its school years, social values, etc. which led the child to stop going to school (Hollister 1986).
2.3.7.2 Dependence and tolerance
Cannabis consumption can lead to psychological dependence; it is estimated that around half of heavy users develop dependence of this type (WHO, 1997). In a German study, one in five respondents admitted to frequently or very frequently consuming more cannabis than they had intended to (Kleiber et al 1997). The tendency to develop physical dependence is only weak. It has been demonstrated in animal experiments by administering an antidote (the receptor antagonist SR 141716A) following chronic administration of cannabis and observing withdrawal symptoms (Aceto et al 1995). Abrupt withdrawal in humans following heavy daily consumption produces autonomic withdrawal symptoms such as nausea, perspiration, trembling, insomnia and loss of appetite (Hollister 1986; Wiesbeck et al 1996). These symptoms regress following renewed administration of cannabis, an observation that corroborates the development of dependence (Adams, Martin 1996). The the dependence profile is classified by the World Health Organization as a distinctive type of dependence, known as cannabis- type dependence.
The development of tolerance is associated with pharmacodynamic changes. Chronic administration of THC has been shown to reduce the number of receptor binding sites (Rodriguez de Fonseca et al 1994), although this appears to be reversible (Westlake et al 1991). The tolerance to the functional and psychological effects of THC observed in animal experiments has also been demonstrated in man, but does not lead the individual to increase the dose of cannabis (Beardsley et al 1986; Hollister 1986). Clear tolerance development has been demonstrated with respect to mood swings, elevated heart rate and impairment of psychomotor functions. The conditions under which tolerance and dependence develop – high doses of THC over a long period – do not correspond to the widespread recreational use of cannabis, and this is why these properties of cannabis do not present a serious problem.
Cannabis is probably the most widely smoked substance in the world after tobacco. In addition to the nicotine in tobacco and the cannabinoids in cannabis, the matter inhaled from both substances contains a large number of other compounds which irritate the respiratory tract and have carcinogenic (cancer- causing) properties (Julien 1997). The effects of tobacco and cannabis on the respiratory system are very probably not additive (WHO 1997), or in other words they cannot simply be added together. However, the cannabis smoker inhales more deeply than the tobacco smoker, allowing four times the quantity of tar to enter the lungs (Hagers Handbuch [...] 1992). Bronchial irritation and inflammation, reduced macrophage and cilia activity (making the removal of particles from the lungs more difficult) and changes to the mucous lining of the respiratory tract have been observed in heavy users of hashish (Hollister 1986; Julien 1997). In general, studies of longstanding cannabis smokers have demonstrated damage to the mucosa in the trachea and bronchi (WHO 1997). Smoking cannabis products is therefore assumed to be associated with an increased risk of lung and bronchial cancers. However, it is difficult to consider the carcinogenicity of cannabis in the lung in isolation because hashish and marijuana smokers are usually also cigarette smokers as well – quite apart from the fact that these two cannabis products are generally smoked in a mixture with tobacco anyway (Hagers Handbuch [...] 1992).
2.3.7.4 Genetic effects and effects on reproduction and pregnancy
An increased rate of chromosomal abnormalities, mainly chromosome breaks and translocations, has been observed among marijuana smokers (Hollister 1986). Changes at the cellular level were reversible in clinical trials (WHO 1997). The clinical significance of these observations is disputed, not least because similar changes can occur in individuals taking commonly prescribed drugs on a daily basis (Hollister 1986; Maykut 1985).
The effects on the concentration of testosterone, estrogen and prolactin in plasma observed in animal experiments have not been reproduced unequivocally in clinical trials with humans (WHO 1997). In women, cannabis consumption leads to lower levels of follicle- stimulating hormone (FSH) and luteinizing hormone (LH), and may affect the menstrual cycle, although these effects are evidently reversible and disappear once the drug is discontinued (Hollister 1986; Maykut 1985).
The good lipid solubility of the cannabinoids allows them to cross the placenta with ease, and they can be recovered from the fetus after just a few minutes. Animal experiments investigating the effects of cannabis consumption during pregnancy have produced varying results. A major study of 12,000 women, 11 percent of whom used marijuana, found shorter gestation periods, longer deliveries, lower birthweights and a higher rate of deformities (Hollister 1986; WHO 1997). However, the impact of cannabis on birthweight is minor compared to the effect of cigarette smoking during pregnancy. Apart from these physical aspects, the possibility cannot be excluded that cannabis may affect the behavior and cognitive functions (e. g. learning ability) of the child. Accordingly, the use of cannabis during pregnancy should be restricted as systematically as the consumption of alcohol and smoking (Hagers Handbuch [...] 1992; Hollister 1986).
2.3.7.5 Effects on the immune system
Animal experiments and cell cultures have shown cannabinoids to affect B and T lymphocytes (e. g. increased susceptibility to infection), although these effects were not pronounced, were fully reversible, and were induced only by very high concentrations in excess of those used by individuals to achieve psychotropic effects (Adams, Martin 1996; Hollister 1986; WHO 1997).
The human immune system is relatively resistant to the immunosuppressive effects of the cannabinoids, and the research carried out so far supports the therapeutic use of 9 -THC even in patients whose immune system has been compromised by other diseases (AIDS, cancer).
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