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Wayne Hall's Cannabis Publications

These publications were selected by Dr. Hall to supplement his lecture titled: "The Cannabis Policy Debate: Finding a Way Forward," presented at the University of Washington in Seattle on Sept. 13, 2000. [more info and slides].

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1. Hall, W., Solowij, N. and Lemon, J. The Health and Psychological Consequences of Cannabis Use. National Drug Strategy Monograph Series No. 25. Australian Government Publication Service, Canberra, 1994.
   ABSTRACT: The following is a summary of the major adverse health and psychological effects of acute and chronic cannabis use, grouped according to the degree of confidence in the view that the relationship between cannabis use and the adverse effect is a causal one.
   [full text]

2. Donnelly, N. and Hall, W. Patterns of Cannabis Use in Australia. National Drug Strategy Monograph Series No. 27. Australian Government Publication Service, Canberra, 1994.
   ABSTRACT: (from the Executive Summary) This review of patterns of cannabis use in Australia was undertaken at the request of the National Task Force on Cannabis with the following aims: 1. to describe contemporary patterns of cannabis use in Australia, and recent changes in them, as can be inferred from the findings of general population, high school and tertiary student surveys of licit and illicit drugs use; 2. to put these contemporary patterns of cannabis use in Australia into perspective by comparing current use with that in Australia over the past 20 years and with contemporary patterns of use in Canada, New Zealand, the United Kingdom, and the United States; and 3. to assess the possible long-term significance of current patterns of cannabis use by examining the available evidence on the 'natural history' of cannabis use, i.e. the proportions of those who experiment with cannabis who continue to use into adult life, become daily users, or go on to use more hazardous illicit drugs.

3. Hall, W. The health and psychological effects of cannabis use. Current Issues in Criminal Justice, 1994, 6, 208-220.

4. Hall, W. and Nelson, J. Public Perceptions of the Health and Psychological Consequences of Cannabis Use. National Drug Strategy Monograph Number 29. Canberra: Australian Government Publishing Service, 1995.
   ABSTRACT: (from the Executive Summary) The survey aimed to discover: 1. What the people believe the health risks of marijuana use to be; 2. How they evaluate these risks in comparison with those of other drugs such as alcohol, tobacco, heroin and amphetamines; and 3. How personal characteristics are related to thses beliefs.
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5. Hall, W. The public health significance of cannabis use in Australia. Australian Journal of Public Health. 1995, 19(3), 235-242. Abstract: A fair appraisal of the public health significance of cannabis use has been hampered by the polarised opinions about its health effects expressed by partisans on both sides of the debate on its legal status. The findings of a recent review of the literature on the adverse health and psychological effects of cannabis are used to estimate the major probable public health risks of cannabis use in Australia. These appear to be, in order of approximate public health importance: adverse psychological effects; motor vehicle accidents; cannabis dependence; respiratory disease; precipitation and exacerbation of schizophrenia in vulnerable individuals; low-birthweight babies; and perhaps subtle cognitive impairment. On current patterns of use, cannabis use is a modest public health concern by comparison with alcohol and tobacco, although given the scale of public health damage caused by the latter drugs, and the currently low prevalence of regular cannabis use, this is not cause for complacency.

6. Donnelly, N., Hall, W. and Christie, P. The effects of partial decriminalisation on cannabis use in South Australia 1985-1993. Australian Journal of Public Health, 1995, 19, 281-287. Abstract: In 1987 the Cannabis Expiration Notice scheme decreased penalties for the personal use of cannabis in South Australia. Data from four National Campaign Against Drug Abuse (NCADA) household drug-use surveys covering the period 1985 to 1993 were analysed to measure the effect of the decriminalisation on cannabis use. The main outcomes used were the self-reported prevalence rates of having ever used cannabis and current weekly use. Logistic regression was used to control for the potentially confounding effects of age and sex. Other outcomes were rates of having ever been offered cannabis and willingness to use cannabis if offered it. Between 1985 and 1993 the adjusted prevalence rate of ever having used cannabis increased in South Australia from 26 per cent to 38 per cent. There were also significant increases in Victoria and Tasmania, and to a lesser extent in New South Wales. The increase in South Australia was not significantly greater than the average increase (P = 0.1). Adjusted rates of weekly use increased between 1988 and 1991 in South Australia, but did not change through 1993. Although the effect was in the direction of a greater increase in South Australia, this was not statistically significant when compared to increases in the rest of Australia (P = 0.07). The greatest increase in adjusted weekly use occurred in Tasmania between 1991 and 1993, from 2 per cent to 7 per cent. Although the NCADA survey data indicate that there were increases in cannabis use in South Australia in 1985-1993, they cannot be attributed to the effects of partial decriminalisation, because similar increases occurred in other states.

7. Hall, W. The health risks of cannabis. Australian Family Physician, 1995, 24, 1237-1240. Abstract: The debate about the legal status of cannabis and its effect on health has polarised public opinion. In the absence of credible non partisan advice, health education about cannabis has been neglected because of uncertainty about what information to present. This paper summarises likely adverse acute and chronic health effects of cannabis that emerged from a peer-reviewed analysis of the research literature undertaken for the National Task Force on Cannabis. From this review, suggestions are offered concerning advice that family physicians can give to their patients about the health risks of using cannabis.

8. Hall, W., Solowij, N. and Lemon, J. A Summary of "The Health and Psychological Effects of Cannabis. Addiction, 1996, 91, 759-762.

9. Hall, W. and Solowij, N. Steering a course between the Charybdis of credulity and the Scylla of scepticism. Addiction, 1996, 91, 770-773.

10. Hall, W. and Nelson, J. Correlates of the perceived health risks of marijuana among Australian adults. Drug and Alcohol Review, 1996, 15, 137-144.

11. Didcott, P., Reilly, D., Swift, W. and Hall, W. Long Term Cannabis Users on the New South Wales North Coast. National Drug and Alcohol Research Centre Monograph Number 30. National Drug and Alcohol research Centre, Sydney, 1997. Abstract: Cannabis is the most widely used drug in Australia but there is little information on the characteristics of long-term regular cannabis users in Australia. We do not have information on: their patterns of cannabis use and the social contexts of cannabis use, the possible health consequences and perceived benefits of cannabis use, the lifestyle of long-term regular users, and the impact of cannabis on users, their families and the communities within which they live. The New South Wales North Coast was chosen as the site of the study of these issues because it is a region where there was a considerable concentration of long-term cannabis users.

    The study had four major objectives. The first was to describe the characteristics of long-term cannabis users in a rural area. The second was to describe their patterns of cannabis and other drug use and the contexts of use. The third was to determine to the extent possible the prevalence and correlates of some of the harmful health, social and psychological effects that have been attributed to long-term cannabis use. The fourth objective was to investigate the attitudes and beliefs of cannabis users, their families and significant others, about the reasons for their use of cannabis, the health and psychological effects of the drug, whether there was a need for treatment, and the effects of law enforcement on their cannabis use.

12. Hall, W. and Solowij, N. Long-term cannabis use and mental health. British Journal of Psychiatry, 1997, 171, 107-108.

13. Swift, W., Hall, W. and Copeland, J. Cannabis dependence among long-term users in Sydney, Australia. NDARC Technical Report No. 47. National Drug and Alcohol Research Centre, Sydney, 1997. Abstract: Cannabis is the most widely used illicit drug in many Western countries. However, by comparison to tobacco, alcohol and the opiates, little is known about its dependence potential, or the patterns and correlates of symptoms of cannabis dependence. More generally, there has been a lack of research into the characteristics and experiences of long term cannabis users, the group arguably most likely to experience dependence. This study provides detailed information on a sample of long-term cannabis users, recruited and interviewed in Sydney, Australia. It aimed to provide further information on their patterns and experiences of cannabis use, and to compare them to a recently studied population of long-term users in rural NSW. Its particular goal was to study the prevalence and nature of cannabis dependence symptoms among long-term, urban cannabis users, using four different dependence measures.

14. Hall, W. The recent Australian debate about the prohibition on cannabis use. Addiction, 1997, 92, 1109-1115. Abstract: This paper outlines the ethical arguments used in the Australian debate about whether or not to relax the prohibition on cannabis use by adults. Over the past two decades a rising prevalence of cannabis use in the Australian population has led to proposals for the decriminalization of the personal use of cannabis. Three states and territories have removed criminal penalties for personal use while criminal penalties are rarely imposed in the remaining states. Libertarian arguments for legalization of cannabis use have attracted a great deal of media interest but very little public and political support. Other arguments in favour of decriminalization have attracted more support. One has been the utilitarian argument that prohibition has failed to deter cannabis use and the social costs of its continuation outweigh any benefits that it produces. Another has been the argument from hypocrisy that cannabis is less harmful than alcohol and so, on the grounds of consistency, if alcohol is legally available then so should cannabis. To date public opinion has not favoured legalization, although support for the decriminalization of personal cannabis use has increased. In the long term, the outcome of the debate may depend more upon trends in cannabis use and social attitudes among young adults than upon the persuasiveness of the arguments for a relaxation of the prohibition of cannabis.

15. Martin, B.R. and Hall, W. The health effects of cannabis: key issues of policy relevance. Bulletin on Narcotics, 1997/1998, 49-50, 85-116.

16. Reilly, D., Didcott, P., Swift, W. and Hall, W. Long-term cannabis use: characteristics of users in an Australian rural area. Addiction, 1998, 93, 837-846. Abstract: AIM: To investigate the characteristics and patterns of cannabis and other drug use among long-term cannabis users in an Australian rural area. DESIGN: Cross-sectional survey of a "snowball" sample of long-term cannabis users.SETTING: The North Coast of New South Wales is an area with high levels of cannabis cultivation and use, and many long-term users. PARTICIPANTS: The study involved 268 long-term cannabis users who had regularly used cannabis for at least 10 years. MEASUREMENTS: A structured interview schedule obtained information on: demographics, social circumstances, patterns of cannabis and other drug use, contexts of use, perceptions about cannabis and legal involvement. FINDINGS: The mean age of the sample was 36 years and 59% were made. The median length of regular cannabis use was 19 years. Most (94%) used two or more times a week and 60% used daily, with a median of two joints per day. Two-thirds (67%) used cannabis in social settings and two-thirds grew cannabis for their own use. The most common reasons for using cannabis were for relaxation or relief of tension (61%) and enjoyment or to feel good (27%). The most commonly reported negative effects were feelings of anxiety, paranoia, or depression (21%), tiredness, lack of motivation and low energy (21%) and effects of smoke on the respiratory system (18%). The majority drank alcohol (79%) and over one-third were drinking at hazardous levels. Most were current (64%) or ex-tobacco smokers (24%). One-quarter (25%) had been charged with possession of cannabis, 11% for cultivation and 6% for supply, with non-drug offences low (8%or less). Overall, three-quarters (72%) believed that the benefits of cannabis use outweighed the risks, 21% felt there was an even balance, and 7% said cannabis had done them more harm than good. CONCLUSIONS: Among long-term cannabis users in this Australian rural area, cannabis use was an integral part of everyday life and it was primarily used in social situations for the same reasons that alcohol use is used in the wider community.

17. Swift, W., Hall, W., Didcott, P. and Reilly, D. Patterns and correlates of cannabis dependence among long-term users in an Australian rural area. Addiction, 1998, 93, 1149-1160. Abstract: AIM: To examine prevalence and correlates of cannabis dependence among long-term cannabis users. DESIGN: A cross-sectional survey of patterns and experiences of cannabis use and dependence. SETTING AND PARTICIPANTS: A snowball sample of 243 long-term cannabis smokers, who were currently smoking 3-4 times a week, were recruited from the New South Wales North Coast, an area long associated with cannabis cultivation and use. MEASUREMENTS: A structured interview was administered, incorporating the following dependence measures: an approximation to a life-time DSM-III-R diagnosis, an approximation to a 12-month ICD-10 diagnosis, and the Severity of Dependence Scale (SDS). FINDINGS: Prevalence of a life-time DSM-III-R diagnosis of cannabis dependence was 57%, while 57% received an ICD-10 dependence diagnosis for the last year. Substantially fewer (15%) of the sample were diagnosed as dependent according to the Severity of Dependence Scale (SDS). Only 26% believed they had a problem with cannabis at least sometimes. There was general concordance between DSM-III-R and ICD-10 measures, but not between these and the SDS. ICD-10 and DSM-III-R dependence diagnoses were modestly correlated with age, life-time illicit drug use and quantity of cannabis use. Principal components analyses of the dependence measures provided little evidence for a unidimensional dependence syndrome for ICD-10 and DSM-III-R criteria. There was strong support for unidimensionality of the SDS. CONCLUSIONS: Symptoms of cannabis dependence were common among these long-term users but only one-quarter perceived that they had a cannabis problem. There was no strong evidence for a unidimensional cannabis dependence syndrome.

18. Hall, W. The respiratory risks of cannabis smoking. Addiction, 1998, 93, 1461-1463.

19. Hall, W. and Solowij, N. The adverse effects of cannabis use. Lancet, 1998, 352, 1611-1616.

20. Hall, W. Cannabis and psychosis. Drug and Alcohol Review, 1998, 17, 433-444.

21. Kalant, H., Corrigal, W, Hall, W. and Smart, R. (eds) . The Health Effects of Cannabis. Addiction Research Foundation, Toronto, 1999.

22. Hall, W. Assessing the health and psychological effects of cannabis use.. In: Kalant, H., Corrigal, W., Hall, W. and Smart, R. eds. The Health Effects of Cannabis. Addiction Research Foundation, Toronto, 1999.

23. Hall, W., Room, R. and Bondy, S. Comparing the health and psychological risks of alcohol, cannabis, nicotine and opiate use. In: Kalant, H., Corrigal, W., Hall, W. and Smart, R. eds. The Health Effects of Cannabis. Addiction Research Foundation, 1999.

24. Chesher, G. and Hall, W. The effects of cannabis on the cardiovascular and gastrointestinal systems. In: Kalant, H., Corrigal, W., Hall, W. and Smart, R. eds. The Health Effects of Cannabis. Addiction Research Foundation, 1999.

25. Hall, W., Johnston, L. and Donnelly, N. The epidemiology of cannabis use and its consequences. In: Kalant, H., Corrigal, W., Hall, W. and Smart, R. eds. The Health Effects of Cannabis. Addiction Research Foundation, 1999.

26. Channabasavanna, S., Paes, M. and Hall, W. Mental and behavioural disorders due to cannabis. In: Kalant, H., Corrigal, W., Hall, W. and Smart, R. eds. The Health Effects of Cannabis. Addiction Research Foundation, 1999.

27. Hall, W. and Swift, W. The THC content of cannabis in Australia: evidence and implications. National Drug and Alcohol Research Centre, Technical Report Number 74, Sydney, 1999. Abstract: A number of commentators in the alcohol and other drugs field have recently claimed that the THC content of cannabis used in Australia has increased between 10 and 30 times over the past two decades. This has raised understandable queries about its role in a possible increase in the adverse health and psychological effects of cannabis use experienced by young people. There is a need to distinguish two different interpretations of this claim: (i) that the average THC content of cannabis plants has increased, and (ii) that the average THC content of cannabis products as consumed by Australian users has increased by 10-30 times. We examine evidence on each claim and discuss the implications for harm.

28. Hall, W. Appraisals of the health effects of cannabis: ideology and evidence. FAS Drug Policy Analysis Bulletin, June 1999, Number 7.

29. Ali, R., Christie, P., Lenton, S., Hawks, D., Sutton, A., Hall, W. and Allsop, S. The Social Impacts of the Cannabis Expiation Notice Scheme in South Australia: Summary Report. National Drug Strategy Research Monograph Number 34, Australian Government Publishing Service, Canberra, 1999.

30. Donnelly, N., Hall, W., and Christie, P. Effects of the Cannabis Expiation Notice Scheme on levels and patterns of cannabis use in South Australia: Evidence from the National Drug Strategy Household Surveys 1985-1995. National Drug Strategy Research Monograph Number 37, Australian Government Publishing Service, Canberra, 1999.

31. Swift, W., Hall, W. and Teesson, M. Cannabis use disorders among Australian adults: Results from the National Survey of Mental Health and Wellbeing. National Drug and Alcohol Research Centre Technical Report 78, Sydney, 1999. Abstract: (from the Executive Summary) The National Survey of Mental Health and Well-Being (NSMHWB) interviewed a representative sample of 10,641 Australians aged 18 years and older about symptoms of DSM-IV and ICD-10 mental health and substance use disorders, and disability and help-seeking associated with these disorders. It provided the first opportunity to examine the prevalence of cannabis use disorders in the adult Australian population. This report presents data on the prevalence of cannabis use, the prevalence and correlates of DSM-IV cannabis use disorders, the DSM-IV dependence symptoms reported and health service utilisation among Australian adults. A limited comparison with ICD-10 cannabis use disorders is presented. The factor structures of DSM-IV and ICD-10 dependence symptoms and agreement between the two diagnostic systems in who is diagnosed with a disorder are also examined.

32. Strang, J., Witton, J., and Hall, W. Improving the quality of the cannabis policy debate: defining the different domains. British Medical Journal, 2000, 320, 108-110. Abstract: The policy debate on cannabis has moved back into prominence in Britain and elsewhere after reports of increases in use during the early 1990s1 and renewed claims about the therapeutic value of marijuana. 2 3 Rational debate has often been obstructed because the media present a forced choice between two sets of views. One of these constructed views is that cannabis is harmless when used recreationally, is therapeutically useful, and hence should be legalised. The other is that recreational use is harmful to health and that cannabis should continue to be prohibited for recreational or therapeutic purposes.4

    This oversimplification of the cannabis debate has prevented a more considered examination of eight conceptually separate issues (box). We believe that a competent consideration of these issues would contribute to a more informed debate about the appropriate public policies that could be adopted towards cannabis use for recreational or therapeutic purposes.

33. Degenhardt, L., Lynskey, M. and Hall, W. Cohort trends in the age of initiation of drug use in Australia. National Drug and Alcohol Research Centre, Technical Report Number 83, Sydney 2000. Abstract: This paper examines Australian population birth cohort trends in the prevalence of use, and the age of initiation of use, of six substances: alcohol, tobacco, cannabis, amphetamines, LSD, and heroin. Data were taken from the 1998 National Drug Strategy Household Survey, which was a representative sample of Australians aged 14 years and over. Nine five-year cohorts were examined in persons born between 1940 and 1984.

34. Hall, W. and Degenhardt, L. Cannabis and psychosis. Australian and New Zealand Journal of Psychiatry, 2000, 34, 26-34.

35. Hall, W. and Babor, T. Cannabis use and public health: assessing the burden. Addiction, 2000, 95, 485-490.

36. Swift, W., Hall, W. and Copeland, J. One year follow-up of cannabis dependence among long-term users in Sydney, Australia. Drug and Alcohol Dependence, 2000, 59, 309-3181. Abstract: Eighty one percent of a sample of long-term cannabis users was followed up at 1 year (162/200). Half (51%) were daily smokers, while 20% had substantially decreased or ceased use. More than half received a dependence diagnosis on each of three measures in the last year, with 44% dependent on all three. Remission was much more common than incidence of dependence. Nevertheless, use and dependence patterns were strongly related over time. Longitudinal analyses revealed that quantity of use and severity of dependence at baseline were the primary predictors of those same variables at follow-up. These data suggest that cannabis use and dependence are fairly stable among long-term users.

37. Hall, W. The cannabis policy debate: Finding a way forward. Canadian Medical Association Journal, 2000, 162, 1690-1692.

38. Donnelly, N., Hall, W., and Christie, P. Effects of the Cannabis Expiation Notice System on the prevalence of cannabis use in South Australia: Evidence from the National Drug Strategy Household Surveys 1985-1995. Drug and Alcohol Review, 2000, 19, 267-271.

39. Darke, S., Ross, J., Hando, J., Hall, W. and Degenhardt, L. Illicit Drug Use in Australia: Epidemiology, Use Patterns and Associated Harm. National Drug Strategy Monograph Number 43. Commonwealth Department of Health and Aged Care, Canberra, 2000.

40. Lynskey, M. and Hall, W. Educational outcomes and adolescent cannabis use. NSW Department of Education and Training, Sydney, 2000.

41. Degenhardt, L., Hall, W. and Lynskey, M. Cohort trends in the age of initiation of drug use in Australia. Australian and New Zealand Journal of Public Health, 2000, 24, 419-424.

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