Complications in Comparing Alcohol and Cannabis

1. Complications in comparing
alcohol and cannabis
Wayne Hall
University of Queensland Centre for
Clinical Research
and
National Addiction Centre
Kings College London

2. Alcohol and cannabis comparisons:
Central to the case for liberalization
• Comparisons clearly favour cannabis
• Acute effects: overdose; accidents; violence; suicide
• Chronic effects: cirrhosis, cancers, neurological
• Additional appeal of argument from hypocrisy:
• Why is a less harmful drug prohibited while a more
dangerous one is freely available?
• Comparisons confounded by legal status
• Public health impacts partially reflect effects of prohibition
• Far fewer regular cannabis users than regular drinkers
• Shorter cannabis use careers than alcohol use

3. Gerrymandered comparisons
• Standard estimates underestimate dependence risk:
• Anthony et al: 9% vs 15% in early 1990s
• But only 1/3 of users at risk of dependence (> 100 uses):
• Dependence risk among these users was: 27%
• Australian twins (2590) users only ¼ did so
• Dependence risk among these users was: 57%
• Use concentrated among daily users
• Most cannabis users at low risk
• But most cannabis consumed in ways that put user at risk
• Just like alcohol, tobacco and gambling

4. Possible increased risks post-legalisation
• Increased potency of products
• Edibles: user misadventures and poisonings
• concentrates: HBO
• Cardiovascular risks
• French studies of strokes and MI in young men
• Case control studies; EMCDDA ER attendances
• Psychotic syndromes
• DiForti studies of skunk; synthetic cannabinoids
• Dependence risk
• GDS showing more symptoms among skunk users

5. Cannabis and cognitive and social performance
• Correlations between daily cannabis use and
• Early school drop out
• Welfare dependence in adulthood
• Poorer quality of life in adulthood
• Sustained daily use and cognitive impairment
• Case control studies: psychometric; neuroimaging
• Cohort studies: New Zealand and USA
• Causation contested by reform advocates:
• Not the drug but the user
• Cannabis most attractive to least cognitively able

6. Regulatory Challenges
• Characteristics of cannabis
1. Performance degrading
2. Dependence producing
3. Modest adverse health effects
4. Few externalities
• Case for regulation depends on 1 and 2
• Minimised by many advocates of reform
• Case for reform based on: 3 and 4
• Implication: regulate cannabis like alcohol, only less so

7. What do we know about alcohol regulation?
• Progressive liberalisation over recent decades
• Treated like an ordinary commodity
• Decreased restrictions and lower prices
• Regulatory capture
• Maximise heavy use
• Blame the drinker for problems
• Socialise the losses: tax payer pays the tab
• Emphasise education not regulation and taxes

8. Health educational challenges
• Developing credible health advice for young people
• “Just say no” is not enough
• Use in moderation: what’s that?
• Delay using until adulthood: a goad to adolescent use for some
• Post-repeal amnesia re risks of regular cannabis use
• Over-compensation for past exaggerations of risks
• Decline in the credibility of public health advice
• Analogue in 1940s and 1950s post repeal NAP
• Liver cirrhosis, psychosis and alcoholism
• Dismissed as temperance propaganda