Three interesting articles in the Lancet (the doctors mag) this week. Interesting because they take a hard look at the present drug laws just as the Home Affairs Committee is about to start its investigation into UK drug laws.
You can see the three papers here, you do need to register but it’s free
“Extent of illicit drug use and dependence, and their contribution to the global burden of disease”
Starts with this summary:
This paper summarises data for the prevalence, correlates, and probable adverse health consequences of problem use of amphetamines, cannabis, cocaine, and opioids. We discuss findings from systematic reviews of the prevalence of illicit drug use and dependence, remission from dependence, and mortality in illicit drug users, and evidence for acute and chronic effects of illicit drug use. We outline the regional and global distribution of use and estimated health burden from illicit drugs. These distributions are likely to be underestimates because they have not included all adverse outcomes of drug use and exclude those of cannabis—the mostly widely used illicit drug. In high-income countries, illicit drug use contributes less to the burden of disease than does tobacco but a substantial proportion of that due to alcohol. The major adverse health effects of cannabis use are dependence and probably psychotic disorders and other mental disorders. The health-related harms of cannabis use differ from those of amphetamine, cocaine, and opioid use, in that cannabis contributes little to mortality. Intelligent policy responses to drug problems need better data for the prevalence of different types of illicit drug use and the harms that their use causes globally. This need is especially urgent in high-income countries with substantial rates of illicit drug use and in low-income and middle-income countries close to illicit drug production areas.
This is the first in a Series of three papers about addiction
Illicit drugs are drugs for which non-medical use has been prohibited by international drug control treaties for half a century because they are believed to present unacceptable risks of addiction to users.
The illegality of opioids, amphetamines, cocaine, and cannabis precludes the accurate estimation of how many people use these drugs, how many people are problem users, and what harms their use causes.
An estimated 149—271 million people used an illicit drug worldwide in 2009: 125—203 million cannabis users; 15—39 million problem users of opioids, amphetamines, or cocaine; and 11—21 million who injected drugs.
Levels of illicit drug use seem to be highest in high-income countries and in countries near major drug production areas, but data for their use in low-income countries are poor.
Cannabis use is associated with dependence and mental disorders, including psychoses, but does not seem to substantially increase mortality.
Adverse health outcomes such as mental disorders, road-traffic accidents, suicides, and violence seem to be increased in opioid, cocaine, and amphetamine users. To what extent these associations are causal is unclear, because confounding variables are not always controlled and quantification of risk is poor.
This absence of consistency in measurement and potential biases poses major challenges for cross-national comparisons. The best strategy is to look for convergence of results from different indirect methods of estimation
The global number of cannabis users was estimated at 125—203 million people (2·8—4·5% of the global population aged 15—64 years in 2009). The highest levels of recorded use were in the established market economies of North America, western Europe, and Oceania.
Studies in high-income countries, with high levels of cannabis use, have reported a common temporal ordering of drug initiation—alcohol and tobacco, followed by cannabis use, and then other illicit drugs. This pattern persists after control for possible confounders.
To make a causal inference it is necessary to document an association between drug use and the adverse outcome, confirm that drug use preceded the outcome, and exclude alternative explanations of the association, such as reverse causation and confounding
Several things are apparent. First, the risks of cannabis use are much smaller than those of other illicit drugs, largely because cannabis does not produce fatal overdoses and it cannot easily be injected. Second, the quality of evidence varies widely across drug and health outcomes—data for cannabis are largely from prospective population-based cohorts, whereas data for the other drug types are from selected cohorts of treated opioid, cocaine, and amphetamine users.
Cannabis use impairs cognitive and behavioural functions, especially for sustained-attention tasks, so the risk of road-traffic accidents can increase if users drive while intoxicated. Controlled studies have recorded statistically significant deficits in driving performance, but studies under more realistic road conditions report more impairment to a lesser extent. Case-control studies have recorded weak associations between cannabis use and culpability for road-traffic accidents, with higher risks in individuals who use more cannabis. These risks are less than those for alcohol,
The relative contribution of cannabis use to road-traffic accidents will vary between countries according to the prevalence of cannabis use and access to motor vehicles.
More heroin injectors meet dependence criteria than do cannabis smokers.
A consistent association exists in longitudinal studies between early onset of cannabis use, regular cannabis use, and a later diagnosis of schizophrenia, which increasing evidence suggests is not caused by confounding. Meta-analyses of prospective population-based studies have noted a doubling of the risk of psychotic outcomes in regular cannabis users, after controlling for confounders, and that the age of onset of schizophrenia is about 2·7 years earlier for cannabis users who develop the disorder. Cannabis use is a biologically plausible contributory cause of schizophrenia in vulnerable individuals
A less consistent association exists between cannabis use and depression, and the evidence for a causal role between cannabis use and depression is less convincing than it is for psychotic symptoms and disorders.
Reviews have concluded that insufficient evidence is available to decide whether a causal relation exists between cannabis use and suicide.
Cannabis dependence, psychosis, suicide, and road-traffic crashes accounted for 0·2% of the total disease burden and 10% of the burden for all illicit drugs.
Although far from perfect, the existing global burden of disease estimates provide a common metric to compare the harms caused by illicit drugs with those of alcohol and tobacco—regionally and globally—while taking account of differences in prevalence and harms.
Burden of disease estimates do not include the adverse social effects on drug users, such as stigma and discrimination, or the adverse effects that drug users’ behaviours have on public amenity (eg, public drug use, drug dealing, and discarded injection equipment) and public safety (eg, violence between drug dealers, and property crime to finance illicit drug use).
the higher price of illicit drugs probably makes it more likely that some who use illicit drugs will engage in criminal activities to finance their use (eg, by drug dealing, property offences, and fraud). Furthermore, violence is often associated with illicit drug markets, presenting a risk to the wellbeing of drug users. Cohort studies of opioid users suggest a pooled homicide crude mortality rate of 0·10 per 100 person-years (95% CI 0·07—0·13), and findings from a meta-analysis of toxicological studies of homicide victims show that about 6% of victims tested positive for cannabis, 11% for cocaine, and 5% for opioids. A review concluded that “the distal factors surrounding illicit drug markets appear to play a larger role in illicit drug-related homicide than the proximal effects of [these] substances”. Drug-related law enforcement often comprises a large proportion of the social costs of illicit drug use. Countries that are sites of illicit drug production or trafficking might have substantial social, political, and health disruption from the activities of the large-scale criminal networks involved, as is the case in Afghanistan and Mexico.
The dominant policy focus on supply reduction and criminalisation of drug use can also adversely affect the health and wellbeing of illicit drug users in the following ways: by increasing the health risks of illicit drug use (eg, if users engage in risky injecting to avoid arrest by police); by increasing risks of engaging in sex work or other illegal activities to finance drug use, exposing users to violence and sexual risk; by discouraging treatment-seeking (for fear of negative consequences); by reducing access to interventions that reduce risk, through creating legal obstacles to, or policy limits on, service provision;and by increasing the risks of imprisonment and its attendant health risks.
How much does criminalisation of drugs reduce their prevalence of use? How much of the harm related to illicit drugs derives from their illegal status?
A major unintended consequence of the criminalisation of drug use is the inability to collect high quality data for patterns of use and harms.