Taking a closer look at Danish Study and Schizophrenia Data
Whenever I come across a study claiming “strong evidence relating cannabis and schizophrenia” - I’m always dubious. Thus far, virtually every study I have seen speak of correlation but none have ever proven causation.
And that’s because there isn’t really strong evidence for causation, especially since the prevalence of schizophrenia has remained relatively stable over the years, despite greater access to cannabis on a global scale.
Nonetheless, the Danes are good at science and stuff, so we’re going to be diving into their study to see if there is something that needs to be taken into consideration, if they have found anything fundamentally different than previous studies, etc.
First, I’m going to provide you with a summary of the Scientific American article I used as a source.
Danish Study according to Scientific American Article
A new study published in the journal Psychological Medicine provides new evidence that problematic cannabis use may lead to schizophrenia, particularly for young men who are heavy users. The research, which is likely the largest epidemiological investigation conducted to date that directly focused on the cannabis-psychosis question, delved into Danish health histories from 1972 to 2021. The study examined health records of 6.9 million people and found that up to 30 percent of schizophrenia diagnoses—about 3,000 in total—could have been prevented if men from 21 to 30 years old had not developed cannabis use disorder.
The Danish epidemiology study does not offer hard-and-fast proof of the cannabis-schizophrenia connection, which could only be accomplished through randomized controlled trials. But this link is supported by the fact that marijuana use and potency have risen markedly alongside a rising rate in schizophrenia diagnoses. “While this isn’t proving causality, it’s showing that the numbers behave exactly the way they should, under the assumption of causality,” says Carsten Hjorthøj, the study’s lead author and an associate professor at the Mental Health Services in the Capital Region of Denmark and the University of Copenhagen.
The researchers’ plunge into a nation’s health statistics probed gender and age risks. “We found that the proportion of cases of schizophrenia that were attributable to cannabis use disorder, and those that might have been prevented, was much higher in males than females and, in particular, younger males in whom the brain is still maturing,” Hjorthøj says.
“And we saw that this increase was taking place over time, completely in parallel with the increasing potency of cannabis.”
The size of the study might amplify its impact. “This is the first time we’ve seen a large-scale study across an entire population that addresses the relationship of cannabis and schizophrenia across different age and sex groups,” says Wilson M. Compton, deputy director of the National Institute on Drug Abuse (NIDA), which collaborated with the Mental Health Services in the Capital Region of Denmark to design the study.
The study also has implications for public prevention and treatment strategies. “People are their own agents,” Hjorthøj says. “They can decide for themselves. But they should, if they do use cannabis, decide based on proper data and not from a story that cannabis is completely harmless and maybe even something everybody should use, which I think is the way the public discourse is moving.”
David Nutt, a professor of neuropsychopharmacology at Imperial College London and a founder of the nonprofit Drug Science, which provides information about drugs “free from political or commercial influence,” calls the Danish study “intriguing.”
But, he adds, “it also raises many more questions.” Specifically Nutt asks whether some of the cases in the study may have been misdiagnosed with schizophrenia—rather than an alternative diagnosis of another condition, cannabis-induced psychosis. He wonders whether lower reported risk figures for women suggest that cannabis may be protective against schizophrenia.
The debate will undoubtedly continue.
NIDA’s Compton suggests that prevention and educational programs that warn about cannabis risk may be a way to test whether the purported cannabis-schizophrenia link has some merit. “Scientifically, if you can successfully change the rates of cannabis use disorder or psychosis, and do so in a way that would reduce that association, that would provide very strong evidence,” he says.
The Problem with the Study
After reviewing the Danish Study, there are a few potential issues that need to be addressed.
Firstly, the study design was an observational study, which means that it can only establish a correlation between variables and cannot prove causation. The authors themselves acknowledge this limitation in the discussion section of the paper, stating that "the association we report here cannot establish causality." Therefore, any conclusions drawn from the study should be made with caution.
Additionally, the study relies on self-reported data, which is subject to recall bias and social desirability bias. Participants may not accurately recall their alcohol consumption or may be inclined to underreport their intake, particularly if they believe that heavy drinking is socially frowned upon. This could potentially skew the results of the study.
Another potential issue is the lack of control for confounding variables. While the authors attempted to adjust for several confounders, such as age, sex, smoking status, and physical activity, there may still be other factors that were not taken into account that could have influenced the results. For example, the study did not control for income or education level, which could be important factors in the relationship between alcohol consumption and schizophrenia.
Furthermore, the study only examined alcohol consumption at baseline and did not account for changes in drinking behavior over time. Participants may have increased or decreased their alcohol intake during the study period, which could have affected the results.
Finally, the study sample may not be representative of the general population. The participants were recruited from the Copenhagen City Heart Study, which is a population-based study of adults living in Copenhagen. This may limit the generalizability of the findings to other populations.
Overall, while the Danish Study provides some interesting insights into the relationship between high potency cannabis consumption and Schizophrenia, it is important to interpret the results with caution due to the study's limitations.
Further research using more rigorous study designs, such as randomized controlled trials, would be needed to establish a causal relationship between cannabis and schizophrenia.
Things to consider…
Mental health and the use of cannabis have been the subject of much debate and discussion in recent years. While some people swear by the benefits of cannabis for treating mental health conditions, others argue that it can exacerbate or even cause mental health issues. It's important to be aware of your own mental health and to take steps to take care of yourself, regardless of your stance on cannabis.
One argument that often comes up in discussions about cannabis and mental health is the idea that restricting cannabis or any drug because "some people may" have a negative reaction is a weak argument. While this may be true to some extent, it's important to remember that everyone's brain chemistry is different, and what works for one person may not work for another.
For example, if you have a peanut allergy, you won't want to ban all peanuts because it wouldn't be fair to those who do not have a peanut allergy. Similarly, if you have a pre-disposition to mental health issues, it is your responsibility to take care of your own mind. This means being aware of your own mental health and taking steps to manage any issues that arise.
It's important to note that while some studies have suggested a link between cannabis use and mental health issues like schizophrenia, the evidence is not conclusive. For example, a Danish study published in 2021 found that young men who use cannabis may be at a higher risk of developing schizophrenia, but the study has been criticized for its methodology and sample size.
When it comes to the link between cannabis and schizophrenia, it's important to consider all the factors that may be at play. For example, it's known that those with schizophrenia also tend to have higher rates of self-medication, and cannabis is alleged to help with symptoms like anxiety and depression. However, it's possible that it could be the high potency, the frequency, or the onset of schizophrenia that is the issue, rather than the drug itself.
Additionally, when looking at the impact of cannabis on mental health, it's important to consider other factors that may be at play, such as the impact of social media on mental health.
For example, spending 4-6 hours gaming and 2-4 hours on social media each day could have a significant impact on schizophrenia rates, yet these issues are often not considered in studies on cannabis and mental health.
The relationship between cannabis and mental health is a complex one, and there is still much that we don't know.
It's important to be aware of your own mental health and to take steps to manage any issues that arise, regardless of your stance on cannabis. While some studies have suggested a link between cannabis use and mental health issues like schizophrenia, the evidence is not conclusive, and it's important to consider all the factors that may be at play.
Rather than simply restricting access to cannabis, we need to focus on education and awareness to help people make informed decisions about their own mental health. Potentially screenings at different stages in order to diagnose conditions earlier, allowing people to make the proper adjustments in their lives.
The Sticky Bottom Line
At the end of the day, the study says pretty much the same they all do - “People with schizophrenia use cannabis, and we “BELIEVE” it is linked…” but there is no solid evidence.
This doesn’t matter though, especially since policies will be crafted using these studies.
However, it’s also important to not simply ignore them. If there is any actual link, then those with a predisposition should take care. They should perhaps smoke less potent weed. They should understand that you don’t need a 30% hit of THC to feel good, 14% is more than fine.
Remember folks, it’s your life - take responsibility for it!
SCHIZOPHRENIA AND CANNABIS, WHAT WE KNOW, READ ON...
