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B4: 3 Cannabis HO2 GP Drug & Alcohol Supplement No.10 June 1998 Cannabis Dependence and Treatment Helen Astolfi, Louise Leonard & Deborah Morris Introduction Cannabis is the most commonly used illicit drug in Australia, and in Western society in general1. There has been a steady increase in cannabis use in Australia since the early 1970s, however, rates of cannabis use are not as high as tobacco and alcohol use1. Mostly cannabis is used intermittently, either experimenting with it once or twice or using it occasionally for recreational purposes. The Drug Prevalence of Cannabis Use Approximately one third of Australians over 14 years of age have ever used cannabis1. The prevalence of ever having used cannabis is strongly related to gender and age. Men are more likely to have used cannabis than women, and adults over the age of 40 are much less likely to have used than younger adults. In the past, cannabis has erroneously been classified as a narcotic, a sedative and most recently as an hallucinogen. Cannabis does possess some hallucinogenic properties, together with disinhibiting and sedative effects. Rates of cannabis use are highest among people aged 20-24 years, with over 80% of males and 60% of females from this group having tried cannabis. Use of cannabis usually declines after early adulthood, with only a minority continuing to use regularly. Even in the case of the minority who use daily, the majority of these people cease their use of cannabis by their mid to late 20s1. It is uncommon for people who use cannabis to progress on to develop problems with other illicit drugs. Cannabis is the generic name given to a variety of preparations derived from the herbaceous plant Cannabis sativa. Slang terms for cannabis include marijuana, grass, dope, pot, weed and mull. The cannabis plant produces a sticky resin, which covers the flowering tops and upper leaves. The resin contains the psychoactive ingredient delta-9-tetrahydrocannabinol (THC). THC concentration varies with the forms in which cannabis is prepared for use. The most common preparations are marijuana, hashish and hash oil. Marijuana is prepared from the dried flowering tops (‘heads’) and leaves of the plant. The concentration of THC is determined by the growing conditions, genetic nature and balance of plant matter. The flowering tops or ‘heads’ possess the highest THC concentration (1025%), with the concentration decreasing through the upper leaves, lower leaves, stems (5-10%) and seeds2. Hashish or hash is made up of dried cannabis resin and compressed flowers and is generally sold in hard chunks or cubes. The THC concentration in hashish can be as high as 20-40%. Hash oil is extracted from hashish using an organic solvent and is a Central Coast Area Health Service GP Drug & Alcohol Supplement No. 10 May 1998 highly potent viscous substance. THC concentration in hash oil has been found to be as high as 70%. the social environment and mood of the user The most common form of administration is by inhalation (smoking). Marijuana can be hand rolled into a ‘joint’ with tobacco and smoked, although it is most often inhaled through a water pipe known as a ‘bong’. A bong is a popular implement for smoking because there is little loss of the drug through sidestream smoke and the water cools down the hot smoke. Acute Cognitive Effects Pharmacology of Cannabis The main effects of cannabis are on cognitive functioning. These effects are exerted through cannabinoid receptors that are located in both the hippocampus and cortex of the brain. High densities of cannabinoid receptors also appear in the basal ganglia and cerebellum; this is consistent with the finding that cannabinoids interfere with coordination2. THC is lipid soluble and is stored readily in fatty tissues. As a consequence, traces of cannabinoids can be found slowly escaping from fat tissues, and thus be present in urine, up to two to three months after use of cannabis, therefore, a positive urine test for cannabis is not an absolute indication of recent cannabis use, although higher urinary cannabinoid levels will provide an indication of more recent use2. The Acute Effects of Cannabis Use The use of cannabis can result in a ‘high’ or altered state of consciousness. This state is characterised by emotional changes such as mild euphoria, perceptual changes, and heightened sensory experiences, e.g. listening to music, eating, watching films, etc. The effects of cannabis are highly variable, and depend upon the following2: the dose administration route prior experience with the drug concurrent drug use the user’s expectations of the effects of the drug Cannabis use can affect cognition, causing short term memory impairment. Acute Psychiatric Effects Some individuals have reported unpleasant effects from cannabis use ranging from anxiety to panic attacks, depressed mood, and a fear of ‘going crazy’. However, these effects are mostly found in the inexperienced user, and can usually be managed with reassurance and support. Psychotic symptoms such as delusions and hallucinations can occur in individuals using very high doses of THC, although this is a rare occurrence. These symptoms may also be experienced at lower doses by people who have a vulnerability to psychosis3. Acute Physical Effects The most immediate effect of cannabis use is an increase in heart rate which can last up to three hours. In the young, healthy user, cardiovascular changes are generally clinically insignificant. However, cannabis may adversely affect patients with ischaemic heart disease, hypertension, and cerebrovascular disease. In the susceptible patient, cannabis acts to increase catecholamine production which can cause arrhythmias, and increase heart rate resulting in angina2. Postural hypotension may also be an acute effect of cannabis use. Acute Psychomotor Effects Coordination and reaction time are impaired during intoxication with cannabis4. Of particular concern is the impact of cannabis intoxication on driving ability. Some studies suggest an increased risk of motor vehicle accidents among individuals who drive when intoxicated by cannabis. This increased risk may be due to the combined use of alcohol and cannabis2. Therefore, it is pragmatic to advise cannabis users not to drive a motor vehicle while under the influence of cannabis. Central Coast Area Health Service GP Drug & Alcohol Supplement No. 10 The Effects of Chronic Cannabis Use on Health Evidence suggests that cannabis smoke is mutagenic and shares many of the same carcinogens as cigarette smoke2. The major cancers arising from cannabis use are those involving the respiratory tract and the aerodigestive tract. In addition, there is evidence that habitual marijuana use causes airway abnormalities affecting mainly the large airways; tobacco use alone affects predominantly the peripheral airways and alveoli2. Research suggests that long-term cannabis use may cause chronic bronchitis2. There is a possibility that chronic, heavy cannabis smoking may have subtle effects on the cardiovascular system2. The Psychological Cannabis Use Effects of Chronic A major concern regarding the psychological effects of cannabis use is the impact it has on motivation, particularly in adolescence. Chronic use interferes with developmental tasks, such as educational achievement, separation from parents, forming peer relationships, and making important life choices5. Reproductive Effects Studies carried out on male animals have shown that cannabis use reduces plasma testosterone levels, retards sperm maturation, reduces sperm count and sperm motility, and increases the rate of abnormal sperm production2. Studies on human females have conflicting results. In female animals, studies have shown that chronic cannabis use interferes with ovulation and probably has an inhibitory effect on the female reproductive system2. Pregnancy Pregnant women who smoke cannabis are at risk of a shorter gestation period and giving birth to low weight babies6. Women May 1998 who smoke cannabis at the time of conception or while pregnant may increase the risk of birth defects, although research is inconclusive2. Women should be encouraged to abstain from cannabis when trying to conceive and during pregnancy. Cannabis Dependence For much of the 1960s and 1970s there was a widespread belief that cannabis was not a drug of dependence1. This belief was due to an apparent absence of tolerance to the effects of cannabis or of a withdrawal syndrome, particularly when compared to that of alcohol and opioid dependence. Views on the nature of dependence changed in the late 1970s and early 1980s when the definition of drug dependence, embodied in the alcohol dependence syndrome7, was extended to all psychoactive drugs8. The importance of tolerance and withdrawal symptoms was reduced in favour of a greater emphasis upon continued use of a drug in the face of its adverse effects1. A diagnosis of cannabis dependence2 (DSMIII-R) is made if any three of the following criteria have been present for one month or longer: 1. cannabis is often taken in larger amounts or over a longer period than the person intended 2. there is a persistent desire or one or more unsuccessful efforts to cut down or control cannabis use 3. a great deal of time is spent in activities necessary to get cannabis, e.g. theft, taking cannabis, or recovering from its effects 4. frequent intoxication or withdrawal symptoms when expected to fulfil major role obligations at work, school or home, or when cannabis is physically hazardous 5. important social occupational or recreational activities given up or reduced because of cannabis use 6. continued cannabis use despite knowledge of having a persistent or recurrent social psychological or physical problem that is caused or exacerbated by the use of cannabis 7. marked tolerance Central Coast Area Health Service GP Drug & Alcohol Supplement No. 10 Withdrawal Symptoms Evidence suggests that abrupt cessation of chronic, high doses of THC can produce a withdrawal syndrome that persists for between four days and a week. The cannabis withdrawal syndrome is not medically dangerous. The most common withdrawal symptoms caused by stopping regular use of cannabis include9: anxiety irritability perspiration sleep disturbances moodiness anorexia Uncommon withdrawal symptoms include: tremors nausea/vomiting occasional diarrhoea excessive salivation May 1998 been shown to give a more accurate picture of consumption. Identify Problems Related to Drug Use dependence withdrawal symptoms other medical symptoms psychological & psychiatric symptoms relationship problems social problems legal problems problems at work financial problems Mental State Assessment Conduct a focused mental state assessment where psychiatric symptoms are evident. Physical Examination A brief physical examination focusing on medical complications of cannabis use should also be conducted. Treatment Matching Management of Patients with Cannabis Related Problems Assessment The assessment of a patient who is using cannabis includes: Taking a Drug Use History This should include a history of amount, frequency, duration, route of administration and pattern of use. It should also identify when the patient last used cannabis. A retrospective time line history of cannabis use, is the most accurate way to obtain a drug use history. A retrospective timeline history is taken by starting with “When did you last use cannabis?” Ascertain how much was consumed at that time. Then enquire back through that day “What about during the day?” Tie cannabis consumption to activities “What were you doing during the day?” then, for example, “How much did you use when you went to your friend’s house?” Consumption through each day is enquired about for the last week. The patient is then asked if this was a typical week’s use for them. This method of taking a history has The three main considerations in matching a patient to treatment of cannabis related problems are: what the patient wants the severity of the patient’s cannabisrelated problems the safety of the patient, i.e. risk of suicide or harm to others from psychotic symptoms or depressive symptoms. Another key issue in assessing what strategy is used for patients who are cannabis dependent is their readiness to quit. A useful model in assessing a patient’s motivation is the ‘Stages of Change Model’10 (Figure 1). This model provides a simple method of questioning to determine the ‘stage of change’ of the patient. The model involves four stages and indicates whether the patient: is not ready (pre-contemplation stage) is unsure (contemplation stage) is ready (action stage) has quit, but is at risk of relapse (maintenance stage). Central Coast Area Health Service GP Drug & Alcohol Supplement No. 10 users should be aware of the major including: increased risk of being involved motor vehicle accident if driving intoxicated risk to the respiratory system increased risk of infertility and problems risk of dependence with daily use Relapse Maintenance Action Pre contemplation Contemplation Figure 1 (adapted DiClemente10) from May 1998 Prochaska & This process is active, in that the patient can be assisted through each of the stages in order to achieve the patient’s desired goal. Treatment Approaches There is a widespread view that cannabis dependence does not require treatment because the withdrawal syndrome is so mild and most users can cease their use without assistance. There are, however, a substantial number of cannabis users who seek professional assistance because, as for those who are nicotine dependent, past attempts to cease have failed. For these people, treatment approaches include: brief advice assisted cessation of cannabis use together with education about its acute and chronic effects assistance with withdrawal symptoms skills training in resisting social cues for use self help groups relapse prevention groups outpatient counselling Further research is needed to evaluate the effectiveness of these treatment methods. However, enough is known to advocate less intensive outpatient treatment options over expensive inpatient treatment. Brief advice Abstinence is the simplest advice for those wishing to avoid the probable adverse health effects of cannabis, particularly those whose health is already compromised. Current risks in a while birth Strategies for quitting There are a number of strategies11 that may assist with quitting, particularly in the initial stages. All of the following strategies may help at some stage or another: set a date and stick to it replace cannabis with new activities and interests avoid situations where there is a likelihood of getting stoned it is not necessary to go it alone; ask a friend for support say to others “I don’t get stoned anymore!” Lifestyle changes Quitting cannabis is like learning a new skill; the more effort one puts in, the more skilled one becomes. Success in remaining abstinent is often due to changes in lifestyle, and may include: telling friends “I don’t smoke anymore” changing diet to include healthier foods increasing exercise avoiding stressful situations, or learning to manage stress in ways other than getting stoned meeting new people understanding feelings of anger and frustration avoiding situations that are likely to cause relapse, e.g. avoid parties where smoking is likely, at least for a few months escaping from situations where other people are smoking or are about to smoke a reminder as to why cannabis was given up noticing how many people don’t smoke having someone listen about their lifestyle change Central Coast Area Health Service GP Drug & Alcohol Supplement No. 10 removing all the things from their home that remind the patient of smoking cannabis not replacing cannabis with alcohol and cigarettes Assistance with withdrawal symptoms The vast majority of patients do not suffer distressing cannabis withdrawal symptoms, and do not require medication during withdrawal. However, a small number of patients may require help to negotiate the cannabis withdrawal symptoms. If agitation, sleep disturbance, restlessness and irritability are major problems for a patient, a benzodiazepine (such as diazepam) may be given for up to four days at a dose of 5 mg tds. Benzodiazepines should not be continued beyond four days in these patients. These patients will require support and counselling throughout the four days to a week of withdrawal symptoms. A home detoxification service can assist in the management of these patients during the withdrawal syndrome. Relapse prevention Reverting to old habits is one reason people fail in their attempts to quit. Preventing relapse is an important aspect of treatment and assists the patient in maintaining their behaviour change. The following techniques can be taught to the patient in the early stages of abstinence when there is a high risk of using cannabis again: Delay Delaying the desire to smoke will help to reduce feelings of anxiety and panic. Instead of saying “I will never smoke again”, postpone having a smoke for the next minute, hour or day. When this time is up postpone smoking again. May 1998 Distract Distract one’s mind from smoking when the urge arises. This could include: meditation bushwalking surfing interaction with a friend deep breathing positive imagery Avoid Avoid people and places that trigger the desire to ‘get stoned’, particularly in the first few weeks from the quit date. For example, if going to a party where people will be smoking it may be best to avoid parties for the first couple of months from the quit date. Escape If all the above tactics fail, escaping from the high risk environment will lower the urge to smoke. Taking a break from the situation where other people are smoking or about to smoke, or stepping outside for a brief walk can also help in the patient’s pursuit to cease cannabis use. Lapses Sometimes the urge to ‘get stoned’ can be overwhelming. If patients do relapse it is important they do not think of themselves as failures. Think of it as a lapse in concentration and encourage patients to renew their commitment to quit. Remaining positive encourages patients to be confident that they are capable of achieving their goals. General Practitioners who require further information regarding the management of cannabis dependence can contact the Drug and Alcohol Local Consultancy Service on 0413 276 177. The Local Consultancy Service is for General Practitioners only. Patients can contact the Central Coast Alcohol and Other Drug Service on 4393 4880. Central Coast Area Health Service GP Drug & Alcohol Supplement No. 10 May 1998 References 1. Donnelly, N. & Hall, W. (Eds) 1994. Patterns of cannabis use in Australia. Monograph Series No. 27. Australian Government Publishing Service: Canberra. 2. Hall, W., Solowij, N. & Lemon, J. (Eds) 1994. The health and psychological consequences of cannabis use. Monograph Series No. 25. Australian Government Publishing Service: Canberra. 3. Thomas, H. 1993. Psychiatric symptoms in cannabis users. British Journal of Psychiatry 163: 141-149. 4. Jaffe, J.H. 1985. Drug addiction and drug abuse. In A.G. Gilman, L.S. Goodman & F. Murad (Eds), The pharmacological basis of therapeutics. 7th edition. Macmillan: USA. 5. Baumrind, D. & Moselle, K.A. 1985. A developmental perspective on adolescent drug abuse. Advances in Alcohol and Substance Abuse 5: 41-67. 6. Hatch, E.E. & Bracken, M.B. 1986. Effect of marijuana use in pregnancy on fetal growth. American Journal of Epidemiology 124: 986-993. 7. Edwards, G. & Gross, M.M. 1976. Alcohol dependence: provisional description of a clinical syndrome. British Medical Journal 1: 1058-1061. 8. Edwards, G., Arif, A. & Hodgson, R. 1981. Nomenclature and classification of drug- and alcohol-related problems: a WHO memorandum. Bulletin of the World Health Organization 59: 225-242. 9. Grenyer, B., Solowij, N. & Peters, R. 1996. A guide to quitting marijuana. NDARC: Sydney. 10. Prochaska, J.O. & DiClemente, C.C. 1986. Toward a comprehensive model of change. In W.R. Miller & N. Heather (Eds), Treating addictive behaviors: processes of change. Plenum Press: New York. Central Coast Area Health Service