Focus on Cannabis policy Flashcards
What is the principle ingredient of cannabis that was identified in 1964?
THC
Why is there controversy on the optimal policy approach for cannabis?
Health effects of cannabis are less known, compared to alcohol and tobacco
Why do we currently know less about cannabis than alcohol or tobacco?
> Illegal status of cannabis has tampered research on potential medical benefits
> Cannabis is less harmful than other illicit drugs such as cocaine and heroin
> Most people stop using cannabis on their own when entering adulthood
How have cohort trends in cannabis use evolved?
> 1940-44: 2% of cohorts used cannabis at age 21
> 1975-79:v 60% of cohorts used cannabis at age 21
- AND younger cohorts reporting cannabis use
What are the cannabis use disorders in the ICD and DSM?
- Cannabis misuse
- Cannabis dependence
Criteria similar to other diagnoses
What is the prevalence of cannabis use disorders in most countries?
Most prevalent illicit drug use disorder in most countries
What are the peak age periods for cannabis use disorders?
- Adolescence
- Young adulthood
Is there a cannabis withdrawal syndrome in the nosographies?
Withdrawal syndrome in cannabis use disorders recently added in DSM
What is the prevalence of withdrawal symptoms?
One of the most frequently reported symptoms of dependence: 30%
What is the association between cannabis and schizophrenia?
> Reasonable evidence cannabis use exacerbates schizophrenia
> Consistent evidence cannabis use can precipitate schizophrenia
- consistent risk ratio of 2 (2-fold increase)
- attributable risk to schizophrenia cases: 13%
What is the evidence of biological plausibility of the cannabis-schizophrenia association?
- Cannabinoid-dopamine interaction
- Provocation studies induce transient psychotic symptoms
What does Denise Kandel’s Stage theory on cannabis use (1992) propose?
Invariant sequence of drug use:
- cannabis precedes use of other drugs
BUT it does not mean causation
What is the current evidence on the causality between early cannabis use and subsequent use of other drugs?
Several studies have not been able to invalidate the possibility that early onset cannabis use may increase risk for subsequent use of other illicit drugs
Which pharmacological mechanisms could explain the potential association between early onset cannabis use and subsequent use of other illicit drugs?
> Cannabis and heroin have similar effects on dopamine neurotransmission
> Chronic treatment with THC induces cross-tolerance to amphetamine and opioids in rats
Which evidence invalidates the pharmacological explanation for association between early onset cannabis use and subsequent use of other illicit drugs?
Amount of THC inhaled by humans is significantly lower than dosage administered to rodents in experiments
- between 5000 and 25000-fold lower
What could explain the association between early onset cannabis use and subsequent use of other illicit drugs?
> Initial experiences with cannabis rated as pleasurable
> Early experiences with cannabis perceived as safe
> Access to cannabis may provide access to other drugs
Which argument led the Netherlands to decriminalise cannabis in the 1970s?
Access to cannabis may provide access to other illicit drugs
Is cannabis the only drug with which early onset use is associated to subsequent use of other illicit drugs?
Similar associations for alcohol and tobacco
- early use associated to subsequent use of cannabis and other illicit drugs
What is the state of evidence on the association between cannabis use and motor vehicle accidents?
> Only 9 studies could be included in recent meta-analysis
> Very little empirical evidence about effects of cannabis use on motor vehicle accidents
What does the recent analysis of Asbridge and colleagues (2012) show about the association between cannabis use and motor vehicle accidents?
Driving under influence of cannabis increase by 2-fold the risk of having a motor vehicle accident
- 2.5% of traffic deaths in France
What is the rank of cannabis use as actual cause of death in the United States in 1990 and 2000, compared to tobacco and alcohol?
- First is tobacco
- Illicit drug use is 9th
- > not even cannabis use specifically
What is the evidence on the adverse effects of cannabis use?
Insufficient evidence
Why is there insufficient evidence on the adverse effects of cannabis use?
- Low number of studies assessing whether all cause mortality rate is elevated among heavy cannabis users in general population
What is the prevalence of dependence in tobacco and alcohol use compared to cannabis use in the general population?
Dependence is more prevalent in alcohol and tobacco use compared to cannabis use
Is alcohol more associated to motor vehicle accidents than cannabis?
Yes
> Cannabis:
- 2 to 3-fold increase in risk of MVA
- 2.5% traffic deaths in France
> Alcohol:
- 6 to 15-fold increase in risk of MVA
- 29% traffic deaths in France
What is the contribution of cannabis, alcohol and tobacco to the burden of disease, in terms of DALYs?
- Cannabis: 0.2% of DALYs
- Alcohol: 2.3% of DALYs
(10x higher than cannabis) - Tobacco: 7.8% of DALYs
What limits the conclusions on population level harm from cannabis?
Current patterns of cannabis use:
- cannabis used by fewer people and less frequently than tobacco and alcohol
-> Sparse body of research
What is the dominant policy approach to cannabis use?
Possession and supply of cannabis is ciminalised
What are the key criticisms against the illegality of cannabis possession and supply?
> Social justice
> Costs of justice system
> Illegal status may create barriers for those seeking treatment
> Illegal status may add attractiveness of cannabis amongst youth
What are the current policy alternatives on cannabis?
> Cannabis caution notices
> Commercial provision of cannabis (Colorado)
> Medical marijuana
> Legalisation
What led the state of Colorado to legalise cannabis?
Referendum
-> supplying and using cannabis for recreational purposes is legal
What were the advantages of the legalisation of cannabis in Colorado?
- Reduction of legal problems for users
- Reduction in costs of criminal justice system
- Cannabis and other illicit drug trades separated
- > eliminating ‘gateway effect’ of cannabis (engages subsequent use of other drugs)
- Reduction in stigma to facilitate help-seeking
What is the gateway effect of a drug?
When use of a drug initiates the subsequent use of other drugs
How can the price of legalised cannabis be managed?
Taxation as benefit to state finances
What limits the taxation of legalised cannabis?
Need to undercut the illegal market:
- set inferior price
How can legalised cannabis be innovated?
Product diversification:
- edibles
- cannabinoid infused liquids
- increasing potency
What are the advantages to innovated legal cannabis products?
> Development of non-smoking routes of administration
> Increased use of vaporisers in ‘medical marijuana’ states
> Consistent quality and known THC concentrations
How can clear labelling of legalised cannabis products combat the adverse effects of cannabis use on mental health?
> Recent research: Cannabidiol (CBD) may protect against adverse effects of cannabis
- particularly related to psychosis
- risk of psychosis associated with ‘skunk’ (high THCm low CBD)
> Brands with high levels of CBD would reduce risk of psychosis
=> health benefits of legal cannabis market
What are the epidemiological consequences of legalised cannabis?
> Expected increase in cannabis use
> Expected increase in frequency among established users
> Problems may increase with higher frequency of use
> Problems may decline if these problems are related to illegal status of cannabis
> Reduction in barriers to treatment-seeking
If cannabis is legalised, what would happen whether it is a complement or a substitute for alcohol?
Cannabis legalisation
- if it’s a complement -> encourage alcohol use
- if it’s a substitute -> decrease alcohol use
What would be the components of an optimal policy to regulate a legal cannabis market?
> Heavily taxed
> Limit on sales
> Advertising ban
> Undercut potential black market
> Product control
- on potency
- content ratio between THC and CBD
