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Highs and lows of cannabis
COMMENTARY
11 Hospital Bed Safety Workgroup. Clinical guidance for the assessment and implementation of bed rails in hospitals, long term care facilities, and home care settings. April, 2003: http://www.ahca.org/quality/ bedrails0304.pdf (accessed Nov 17, 2003). 12 Hoffman S, Powell-Cope G, Rathvon L, et al. BedSAFE: Bed safety alternatives for frail elders. http://www.patientsafetycenter.com/ BedSAFE%20for%20best%20practices_5.ppt (accessed Nov 17, 2003). 13 Hanger HC, Ball MC, Wood LA. An analysis of falls in the hospital: can we do without bedrails? J Am Geriatr Soc 1999; 47: 529–31. 14 Myint S, Neufeld R, Dunbar J. Removal of bedrails on a short-term nursing home rehabilitation unit. Gerontologist 1999; 39: 611–14.
Highs and lows of cannabis Evidence that all cannabis use is harmful per se or, failing that, that it fosters progression to incontrovertibly dangerous substances has long been sought by those in authority. Official report after official report has concluded that cannabis is not that bad but governments have declared war anyway, with consequences that are at best amusing, at worst tragic, and often confusing. When the US Navy ran out of hemp from the Philippines in 1941, the country’s farmers were exhorted to go into reverse and grow the formerly banned plant. Official ruthless hostility to the weed was soon revived post-war and embarrassing copies of a propaganda film, part of the Grow Hemp for Victory campaign, mysteriously disappeared. Such absurdities are just part of Martin Booth’s superb book, Cannabis: a history.1 Events in the UK in 2003 illustrate the confusion. First we learned, via headlines which implied that the very fabric of society might be at risk, that a public appointment had gone to someone who had, when a youth, posted a little of the stuff to a friend. The public’s awareness of this unconcealed and trifling offence was followed by the news that, through the Medical Research Council, they were paying for a clinical trial of cannabis in postoperative pain. Then it was announced that the police would not be bothering too much about the discreet social use of cannabis after its UK classification was relaxed from class B to C. Of course, the official government line remained that the drug is both illegal and dangerous. The inconsistency and confusion is on a global scale as different countries struggle to apply the 1961 UN Single Convention to 21st century reality—or wriggle to ignore it. Booth claims that UN action was driven in part by the first commissioner of the US Federal Bureau of Narcotics and also by the absence of evidence that cannabis had any medical value. When the USA ratified the Single Convention in 1967, Bureau chief Harry J Anslinger’s “intolerant reign of disinformation and prejudice” was over but he still had a strong influence on UN thinking. Booth suggests that, historically, US policy on cannabis was influenced by pressure from petrochemical and paper companies afraid of hemp as a competitor. This prolific plant has many uses. More worryingly, though without offering evidence, he accuses WHO of a different conspiracy. Those seeking to change the Single Convention—and it is difficult to see how a more sensible global approach to this drug can be achieved without revisiting that document—may find that the goalposts have moved. Evidence for clinical efficacy, if forthcoming, will not be enough if there now has to be “incontrovertible proof that cannabis is benign”. That goal is beyond commonsense,2 and it will certainly be unattainable if WHO really is suppressing evidence that goes against the UN/US party line. Cannabis is chemically complex and it seems wise for therapeutic research to include nature’s cannabis as well as individual constituents, notably tetrahydrocannabinol. Some activists believe the medical case is proved already but 344
the clinical trial evidence for efficacy in the management of pain and in illnesses such as multiple sclerosis is far from complete.3 The latest trial data4,5 may have dampened commercial enthusiasm.6 Tincture of cannabis is not yet ready to return to the respectability of the world’s pharmacopoeias but research will continue. Quite why evolution has equipped us with cannabinoid receptors is not clear but it has, and pharmacology is experiencing a revolution7,8 similar to that prompted by the discovery of opioid receptors and endogenous opioids a generation ago. On the safety side, a current concern is psychosis.9,10 In an interview with a London newspaper, published 3 weeks before cannabis became class C on Jan 29, 2004, Prof Robin Murray expressed the view that cannabis increasing the risk of onset of pyschosis is “the No 1 problem facing mental health services in inner cities”.11 Any association between cannabis and schizophrenia may not be directly causal12 but the debate underway is both lively and, as far as UK policy is concerned, late. 40 years ago a balanced Lancet contribution, not written by an editorial recruit in hippy mood, gently wondered if legalisation might be worth considering.13 As with similar utterances in later years, that upset a lot of people. Today even politicians sometimes own up to having tried the weed, but treating cannabis more like tobacco or alcohol seems an unlikely option at present. Prevailing policies range from benign acceptance (Netherlands, provided that you are Dutch) to nervous liberalisation (UK), via zero tolerance (Sweden) and on to severe punishment even of users for personal medical reasons (USA) and the death penalty for trafficking (Malaysia)—and all under the umbrella of a “single convention”. US Federal Bureau of Investigation statistics for 2002 include more than 1·5 million arrests for drug-abuse violations, two-fifths of them relating to cannabis14 (and the vast majority of these will have been for possession only). Those involved in the development of UN drugs policy would do well to read Martin Booth’s book as a starting point for a sensible, informed, and independent debate on the status of cannabis in 2004. David Sharp c/o The Lancet, London NW1 7BY, UK 1 2 3 4
5
6 7 8 9 10
11 12
13 14
Cannabis: a history. By Martin Booth. London: Doubleday/ Transworld, 2003, Pp 354, ISBN 0385 603045, £16.99. Hall W, Solowij N. Adverse effects of cannabis. Lancet 1998; 352: 1611–16. Baker D, Pryce G, Giovannoni G, Thompson AJ. The therapeutic potential of cannabis. Lancet Neurol 2003; 2: 291–98. Zajicek J, Fox P, Sanders H, on behalf of the UK MS Research Group. Cannabinoids for treatment of spasticity and other symptoms related to multiple sclerosis (CAMS study): multicentre randomised placebocontrolled trial. Lancet 2003; 362: 1517–26. Bussy DJ, Toogood L, Maric S, Sharpe P, Lambert DG, Rowbotham DJ. Lack of analgesic efficacy of oral delta-9-tetrahydrocannabinol in postoperative pain. Pain 2003; 106: 169–72. Dyer G. Cannabis: an evil weed or a pot of gold? Financial Times Oct 17, 2003: 15. Pertwee RG, Ross RA. Cannabis receptors and their ligands. Prostaglandins Leukot Essent Fatty Acids 2002; 66: 101–21. Iversen L. Cannabis and the brain. Brain 2003; 126: 1252–70. Degenhardt L, Hall W. Cannabis and psychosis. Curr Psychiatry Rep 2002; 4: 191–96. Arsenault L, Cannon M, Poulton R, Murray R, Caspi A, Moffitt TE. Cannabis use in adolescence and risk for adult psychosis: longitudinal prospective study. BMJ 2002; 325: 1212–13. Boggan S. If cannabis is safe, why am I a psychotic? Times (London) Jan 7, 2004: T2, 4–5. Degenhardt L, Hall W, Lynskey M. Testing the hypothesis about the relationship between cannabis use and psychosis. Drug Alcohol Depend 2003; 71: 37–48. Editorial. Pop “pot”. Lancet 1963; 2: 989–90. Federal Bureau of Investigation. Uniform crime reports 2002. Washington, DC: FBI, 2003: section IV, table 4.1.
THE LANCET • Vol 363 • January 31, 2004 • www.thelancet.com
For personal use. Only reproduce with permission from The Lancet publishing Group.
11 Hospital Bed Safety Workgroup. Clinical guidance for the assessment and implementation of bed rails in hospitals, long term care facilities, and home care settings. April, 2003: http://www.ahca.org/quality/ bedrails0304.pdf (accessed Nov 17, 2003). 12 Hoffman S, Powell-Cope G, Rathvon L, et al. BedSAFE: Bed safety alternatives for frail elders. http://www.patientsafetycenter.com/ BedSAFE%20for%20best%20practices_5.ppt (accessed Nov 17, 2003). 13 Hanger HC, Ball MC, Wood LA. An analysis of falls in the hospital: can we do without bedrails? J Am Geriatr Soc 1999; 47: 529–31. 14 Myint S, Neufeld R, Dunbar J. Removal of bedrails on a short-term nursing home rehabilitation unit. Gerontologist 1999; 39: 611–14.
Highs and lows of cannabis Evidence that all cannabis use is harmful per se or, failing that, that it fosters progression to incontrovertibly dangerous substances has long been sought by those in authority. Official report after official report has concluded that cannabis is not that bad but governments have declared war anyway, with consequences that are at best amusing, at worst tragic, and often confusing. When the US Navy ran out of hemp from the Philippines in 1941, the country’s farmers were exhorted to go into reverse and grow the formerly banned plant. Official ruthless hostility to the weed was soon revived post-war and embarrassing copies of a propaganda film, part of the Grow Hemp for Victory campaign, mysteriously disappeared. Such absurdities are just part of Martin Booth’s superb book, Cannabis: a history.1 Events in the UK in 2003 illustrate the confusion. First we learned, via headlines which implied that the very fabric of society might be at risk, that a public appointment had gone to someone who had, when a youth, posted a little of the stuff to a friend. The public’s awareness of this unconcealed and trifling offence was followed by the news that, through the Medical Research Council, they were paying for a clinical trial of cannabis in postoperative pain. Then it was announced that the police would not be bothering too much about the discreet social use of cannabis after its UK classification was relaxed from class B to C. Of course, the official government line remained that the drug is both illegal and dangerous. The inconsistency and confusion is on a global scale as different countries struggle to apply the 1961 UN Single Convention to 21st century reality—or wriggle to ignore it. Booth claims that UN action was driven in part by the first commissioner of the US Federal Bureau of Narcotics and also by the absence of evidence that cannabis had any medical value. When the USA ratified the Single Convention in 1967, Bureau chief Harry J Anslinger’s “intolerant reign of disinformation and prejudice” was over but he still had a strong influence on UN thinking. Booth suggests that, historically, US policy on cannabis was influenced by pressure from petrochemical and paper companies afraid of hemp as a competitor. This prolific plant has many uses. More worryingly, though without offering evidence, he accuses WHO of a different conspiracy. Those seeking to change the Single Convention—and it is difficult to see how a more sensible global approach to this drug can be achieved without revisiting that document—may find that the goalposts have moved. Evidence for clinical efficacy, if forthcoming, will not be enough if there now has to be “incontrovertible proof that cannabis is benign”. That goal is beyond commonsense,2 and it will certainly be unattainable if WHO really is suppressing evidence that goes against the UN/US party line. Cannabis is chemically complex and it seems wise for therapeutic research to include nature’s cannabis as well as individual constituents, notably tetrahydrocannabinol. Some activists believe the medical case is proved already but 344
the clinical trial evidence for efficacy in the management of pain and in illnesses such as multiple sclerosis is far from complete.3 The latest trial data4,5 may have dampened commercial enthusiasm.6 Tincture of cannabis is not yet ready to return to the respectability of the world’s pharmacopoeias but research will continue. Quite why evolution has equipped us with cannabinoid receptors is not clear but it has, and pharmacology is experiencing a revolution7,8 similar to that prompted by the discovery of opioid receptors and endogenous opioids a generation ago. On the safety side, a current concern is psychosis.9,10 In an interview with a London newspaper, published 3 weeks before cannabis became class C on Jan 29, 2004, Prof Robin Murray expressed the view that cannabis increasing the risk of onset of pyschosis is “the No 1 problem facing mental health services in inner cities”.11 Any association between cannabis and schizophrenia may not be directly causal12 but the debate underway is both lively and, as far as UK policy is concerned, late. 40 years ago a balanced Lancet contribution, not written by an editorial recruit in hippy mood, gently wondered if legalisation might be worth considering.13 As with similar utterances in later years, that upset a lot of people. Today even politicians sometimes own up to having tried the weed, but treating cannabis more like tobacco or alcohol seems an unlikely option at present. Prevailing policies range from benign acceptance (Netherlands, provided that you are Dutch) to nervous liberalisation (UK), via zero tolerance (Sweden) and on to severe punishment even of users for personal medical reasons (USA) and the death penalty for trafficking (Malaysia)—and all under the umbrella of a “single convention”. US Federal Bureau of Investigation statistics for 2002 include more than 1·5 million arrests for drug-abuse violations, two-fifths of them relating to cannabis14 (and the vast majority of these will have been for possession only). Those involved in the development of UN drugs policy would do well to read Martin Booth’s book as a starting point for a sensible, informed, and independent debate on the status of cannabis in 2004. David Sharp c/o The Lancet, London NW1 7BY, UK 1 2 3 4
5
6 7 8 9 10
11 12
13 14
Cannabis: a history. By Martin Booth. London: Doubleday/ Transworld, 2003, Pp 354, ISBN 0385 603045, £16.99. Hall W, Solowij N. Adverse effects of cannabis. Lancet 1998; 352: 1611–16. Baker D, Pryce G, Giovannoni G, Thompson AJ. The therapeutic potential of cannabis. Lancet Neurol 2003; 2: 291–98. Zajicek J, Fox P, Sanders H, on behalf of the UK MS Research Group. Cannabinoids for treatment of spasticity and other symptoms related to multiple sclerosis (CAMS study): multicentre randomised placebocontrolled trial. Lancet 2003; 362: 1517–26. Bussy DJ, Toogood L, Maric S, Sharpe P, Lambert DG, Rowbotham DJ. Lack of analgesic efficacy of oral delta-9-tetrahydrocannabinol in postoperative pain. Pain 2003; 106: 169–72. Dyer G. Cannabis: an evil weed or a pot of gold? Financial Times Oct 17, 2003: 15. Pertwee RG, Ross RA. Cannabis receptors and their ligands. Prostaglandins Leukot Essent Fatty Acids 2002; 66: 101–21. Iversen L. Cannabis and the brain. Brain 2003; 126: 1252–70. Degenhardt L, Hall W. Cannabis and psychosis. Curr Psychiatry Rep 2002; 4: 191–96. Arsenault L, Cannon M, Poulton R, Murray R, Caspi A, Moffitt TE. Cannabis use in adolescence and risk for adult psychosis: longitudinal prospective study. BMJ 2002; 325: 1212–13. Boggan S. If cannabis is safe, why am I a psychotic? Times (London) Jan 7, 2004: T2, 4–5. Degenhardt L, Hall W, Lynskey M. Testing the hypothesis about the relationship between cannabis use and psychosis. Drug Alcohol Depend 2003; 71: 37–48. Editorial. Pop “pot”. Lancet 1963; 2: 989–90. Federal Bureau of Investigation. Uniform crime reports 2002. Washington, DC: FBI, 2003: section IV, table 4.1.
THE LANCET • Vol 363 • January 31, 2004 • www.thelancet.com
For personal use. Only reproduce with permission from The Lancet publishing Group.