In a landmark national study, the Canadian Centre for Addiction and Mental Health (CAMH) explored the social impacts of 16 substances, including alcohol, cocaine, marijuana, opioids, methamphetamine and nicotine. Published in the Journal of Psychopharmacology, the study concluded that out of all substances studied, alcohol leads to the most destruction throughout Canada.
“This is the first time this approach has been used to assess drug harms in Canada, and it gives us a much more complete picture than we had before,” said JF Crépault, senior policy advisor and lead author of the study in a recent press release. “When we look at harm to people who use drugs and harm to others together, alcohol clearly stands out. Our findings highlight a major gap between the harms linked to alcohol and the way it is currently regulated in Canada.”
The study was conducted by using multi-criteria decision analysis (MCDA), a comprehensive research method that allows for multiple objectives to be considered when forming a conclusion, allowing researchers to engage with questions to which there may be no one single outcome. As a result, MCDA allows researchers to form cohesive links between a multitude of consequences that occur when drugs are used.
Researchers analyzed short- and long-term physical, mental and social harms that occur when drugs are used, along with how these actions harm others. Loss of life, declining physical health, economic cost and environmental damage were some of the factors that researchers considered.
Also included in the study was a national panel of 20 experts that initially gave each substance a score from 0-100 relating to 16 types of possible harm. Following this, the panel considered the relevance of each kind of harm. The scores were combined to create an overall score that corresponded to each substance. Alcohol scored 79/100.
Following alcohol, nicotine scored a 45/100, while opioids scored a 33, and cocaine a 19. Methamphetamine had the second to lowest score, clocking in at 19. Cannabis scored the lowest, a 15 out of 100.
“Some substances, including opioids, cocaine and methamphetamine, rank very high even though far fewer people use them, because the harms are so severe,” said Dr. Jürgen Rehm, senior author of the study, and senior scientist at the Institute for Mental Health Policy Research, in the press release. “Alcohol combines serious harms with very widespread use, which is why it causes the greatest total harm in Canada.”
Other MCDA studies conducted in the U.K., Australia, and European Union have found similar results, revealing a complex and normalized chokehold that alcohol possesses globally. Researchers also considered how the results of the study could translate into national policy.
The key message here is that harm is not just about what a drug does to the body,” continued Crépault. “How a drug is regulated shapes who uses it, how it is used, and how much harm it causes. Evidence-based policy can significantly reduce harm, and governments have a real opportunity to use regulation to protect public health.”