Nora Volkow, MD , is Director of the National Institute on Drug Abuse (NIDA) in the United States. In her presentation she reviewed the recent trends in cannabis use in the USA and the effects of cannabis on the brain.
The use of cannabis is going up in the USA. Each year approximately 2.4 million people consume cannabis for the first time. This is problematic because new users tend to be young. For any cannabis user, that individual is at greater risk for progressing into addiction. The earlier substance use is initiated, in the teenage years, the greater the likelihood of later problems. For this reason, the single most important interventions are those focused on prevention, specifically preventing teens and young people from initiating substance use.
Dr. Volkow shared data from the longitudinal nationally representative Monitoring the Future Study which collects self-report data from students in the USA in 8th, 10th and 12th grades. Some cannabis users are missing in the data because regular use of cannabis is associated with dropout in school.
There is no biological justification to make a differentiation between legal and illegal drugs. Drugs stimulate the brain. The release of dopamine stimulates the nucleus accumbens. The brain was not developed to take drugs but pleasures like food and sex are for biological purposes, specifically survival and procreation.
There are many cannabinoids in cannabis, but THC stimulates the reward centers in the brain. The endocannbinoid system is important for many things in the brain and helps regulate functions related to brain development, memory/cognition, motivational systems and reward, appetite, immunological function, reproduction, movement coordination, and pain regulation and analgesia. Cannabinoids have tremendous potential for medical uses, but not as smoked cannabis.
Data clearly shows that cannabis is addictive. About 9% of cannabis users become addicted, but that figure jumps to 16% if a person initiates use during adolescence.
It is not a fair to compare all drugs for their addictive potential because there is a difference in their legal status. In terms of addictive potential, the numbers for alcohol and tobacco are worse but what drives their use is their legality. If cannabis becomes legal we can expect increases in use and in the adverse consequences of that use.
Many useful studies on drug use outcomes focus on twin pairs because the subjects are genetically identical and share the same environment. The risk for developing later addiction to a wide array of drugs is much greater when you use cannabis before age 17. There is something about the drug itself that is beyond genes and the environment. Its use may be priming the brain for addiction, and changing the brain.
Cannabis negatively affects the brain including cognitive function. These findings are sometimes dismissed because in some studies it has been shown that the brain recovers. Thanks to new imaging techniques we can look at biochemistry and see the long-term impact of cannabis use on the brain. We have documented brain abnormalities associated with long-term heavy cannabis use. Among chronic cannabis users, two areas of brain, the amygdala and hippocampus, have reduced volumes. These findings have been replicated.
In terms of brain development, the Dunedin Study examined young people from age 13 through age 32. They were evaluated for premorbid function, during adolescent and in adulthood. Controlling for premorbid IQ, research has shown that show individuals that used cannabis during adolescence had lower adult IQ. The more they used cannabis, the worse the outcome. Individuals that did not use cannabis showed no IQ loss or even showed a slight increase in IQ. The decline in IQ among cannabis users was significant, up to 8 points. This can mean the difference between being successful in school or not being able to carry workload of education.
We know from research that early initiation of long-term cannabis use decreases axonal fiber connectivity. Compared to non-users, there is a profound decrease in connectivity density of specific pathways; these are localized but profound differences. This is in one of the main hubs of the brain which is important for personal awareness. Motivation is crucial for us to succeed and to improve the quality of life for others. Moreover, chronic cannabis users from ages 14 to 21 show less achievement later from ages 21 to 25.
There is a broad body of research that shows the negative impact of cannabis use on the brain, and associations with lowered achievement, psychosis and schizophrenia. New research exists on the increase risk of developing schizophrenia as a function of genotype. Research shows that individuals with a specific genotype increases the likelihood of schizophrenia 7-fold.
Research on the effect of high potency cannabis on risk of psychosis suggests that higher THC content increases the risk of psychosis, not taking into account genotype.
The cannabis available today has a dramatically greater level of delta-9-THC than in years past. Over a 12-year period THC content increased 50% in the USA.
A study of THC levels in drivers suspected of driving under the influence showed greater THC concentrations.
In the USA, cannabis-related treatment admissions increased from 1993 and 2007. It is argued that the criminal justice system is driving admissions for cannabis. But given that the US laws are much harder for cocaine and heroin, we do not see increases in cocaine and heroin admissions. Additionally, emergency department visits related to cannabis increased from 2004 to 2008.
Legal changes with regard to cannabis in the USA began with medical marijuana. It is known that states that have changed the legal status of cannabis have higher rates of cannabis use, leading to increases in dependence on cannabis. It may be that these states had greater levels of use before the legal changes, could be why these states approved the changes.
In Colorado, the proportion of drivers involved in fatal motor vehicle crashes that were positive for cannabis has increased dramatically since the commercialization of the drug in 2009 (with “medical marijuana”).
Dr. Volkow ended her presentation by emphasizing the importance of prevention. Perception of harm from use of cannabis is related to cannabis use. Knowledge profoundly affects adolescents’ behavior. This is why the USA campaign to reduce tobacco use was effective. Adolescents understood the negative effects of tobacco and how they were being manipulated by the industry.
There is now a new cannabis industry that expects to make billions of dollars. It will promote the idea that cannabis use is safe. The brain is not objective. If something is legal, its use is more accepted. It would be great to have a drug that makes you feel great that doesn’t produce any negative or adverse consequences. But we know that it is not possible.
Moving forward, an important priority is to conduct a large, longitudinal study, involving the USA and other countries, is to track the consequences of drug use, from pre-adolescence (e.g. age 10 or 11) through adulthood (e.g. age 21). Now is the time for this important study. Technology has evolved so that it can be done. The results of this study will be essential for policy and education. Adolescents are smart and we must provide them with objective, scientific evidence.
Mike Sabin recognized that the World Federation Against Drugs and like-minded organizations are holding back the tide to promote effective balanced drug policies. Two primary challenges we face globally are the mass-normalization of drug-taking and the perceived inevitability of drug legalization. These ideas are creating great challenges to parents and communities throughout the world.
Given the high potency of drugs and the normalization of their use, it is no surprise that we are seeing an increase in drug-related harms. Even when we do see decreases in some drug use, much of the use is more harmful because of the way in which the drugs are used.
New Zealand implemented a regulated system for new psychoactive substances (NPS) to reverse the onus of proof of safety by putting it on the manufacturers of these drugs. They must prove that these substances are low risk. Under this measure, no drug of abuse would pass the low-risk test.
Mr. Sabin’s overarching message was that the chemical nature of a drug will never be altered by its legal status. When individuals advocate for legalization or regulation of drugs as the way forward, they often reference alcohol as the model. It is ironic because alcohol is so widely used and leads to more harm.
Mr. Sabin noted that it is up to us to ensure that the harms from permissive drug policies are articulated to politicians and lawmakers, and those involved in UNODC, but also to parents. In the interim we need to be focused in what we can do moving forward. We need to identify how we influence a change of direction among legislators and among a potential drug-using population.
He reviewed some of the myths perpetuated by the drug legalization community. The first myth is that harm reduction is the way forward. The term “harm reduction” as a valid treatment intervention has been taken over by the legalization movement that say the goal of drug policy is to reduce harm. But the goal of policy should be to prevent use, then provide interventions to stop that use, and then harm reduction.
He noted that the evidence used to promote drug legalization is cherry picked. The myth that prohibition didn’t – and doesn’t – work is misinformed. In the USA, alcohol use was lowest during prohibition.
Mr. Sabin encouraged the audience to shift the narrative of our policy goals from being “anti-drug” to “pro-brain” because that is what we are working to save.
There is a common misconception that drug use is inevitable, that most people will use drugs. But the truth is that the vast majority of the world population does not use drugs..
Finally, looking at drug policy from a human rights perspective is important. We must think about human rights at a societal level. At what stage is it right that an individual’s rights be usurped by the rights of collective society?
He encouraged all to collect evidence and target that evidence to people – encourage, mentor and educate young people that our work is about being pro-brain. We must counter the expectation that drug use is a part of normalized life.
It is important in our work to focus on the fact that whatever the drug problem costs financially in supply reduction and treatment it will only cost one tenth to achieve successful prevention.
Robert L. DuPont, MD , President of the Institute for Behavior and Health, Inc. noted that the groups calling for drug legalization present themselves as the “future” of drug policy, claiming that prohibition is the past. But Mr. Raymon Yans shared how the UN treaties came to be; they were in response to a free drug market that had catastrophic effects. The UN drug conventions focus on limiting drug availability and use for medical practice and scientific research. To call it “prohibition” is to misunderstand the history.
The legalization movement starts with cannabis but extends to all drugs, and the consequences of which would be extensive. The consequences of cannabis legalization and the commercial exploitation of the drug, will be tipping point to create a change in thinking. The idea of drug legalization can only exist under a restrictive drug policy.
With new permissive drug policies in place it is critical to assess their consequences. Dr. DuPont explained that in the USA, in the states of Colorado and Washington where cannabis was legalized and commercialized, the policy decision was not that of the state governors or legislators. The decision in each of the states was driven by money (well-financed campaigns) and voted by people of these two states.
Dr. DuPont reminded the audience that drugs of abuse are chemicals that stimulate the brain and produce reward. They also impair cognition. The discussion of cannabis laws distracts us from the drug threats that are new – new psychoactive drugs and prescription drug abuse. In the USA, there are now more overdose deaths than fatal motor vehicle crash deaths.
Dr. DuPont concluded by thanking those in attendance and the leadership of the World Federation Against Drugs. He said, “You alone can do it. But you cannot do it alone.” This is true as we work to turn the tide to develop drug policies that are favor of public health, productivity, and protecting the brain. He is extremely optimistic about what we can do, even against the odds that are daunting from time to time.
To develop stronger political influence, we need to be more active in drug debates. This must be transformed into more active action in Europe and across the world. We need to recruit members and to be sure that we reach the public in a better way.
While we have seen some changes in policies that are concerning there are also good reasons to be optimistic. Some European countries now show excellent results in youth surveys related to tobacco, alcohol and drugs. Some countries like Iceland that had disturbing numbers of substance use; they developed a prevention program showing that together with Sweden, Norway and some others that use can be reversed and is now low.
Mr. Reme reinforced the need to work together to make important changes moving forward.