According to the headline of a recent article on News24, “Regular cannabis use puts young people at higher risk for self-harm and death, a new study finds.“
No! That headline is extremely misleading. The article includes a link to the study (which is very good practice) but, unfortunately, I only have access to the abstract (a short summary of the research). However, even with just that we can see several problems immediately.
“Regular cannabis use…”
It was not just regular cannabis use, the study was looking at cannabis use disorder. Cannabis use disorder is diagnosed by a person presenting two or more of a whole list of symptoms. These includes things such as “There is a persistent desire or unsuccessful efforts to cut down or control cannabis use,” “Important social, occupational or recreational activities are given up or reduced because of cannabis use” and “Recurrent cannabis use in situations in which it is physically hazardous.” In fact, “regular use” itself is not a diagnostic criterion at all.
The use of the word “puts” implies causation; that the cannabis use is what is responsible for the increased risk of self-harm. That is not what the study showed. The study shows that there is an association between cannabis use disorder and self harm in youth with mood disorders but that does not mean that the cannabis use was the reason for the increased risk. Correlation is not causation! Another possibility is that people who experience more extreme symptoms of mood disorders, and are therefore more likely to self harm, are also more likely to abuse cannabis, perhaps as a way to cope. Cannabis use might have a causal role in the increased risk of self harm but this study does not appear to show that.
This study was not about young people and cannabis; it was about young people who also have a diagnosed mood disorder. If a youth does not have a mood disorder then the findings here do not apply to them. You can not generalise findings from a specific sub-group of a population to the population as a whole.
“…a new study finds.”
While this is true, the article fails to put this study in context. A single study is interesting but it can be dangerous to draw broad conclusions from it, especially for people that are not familiar with the field. Is this study an outlier that is contrary to the established body of work or is it one of several studies showing the same thing? I don’t know. But knowing is important and is something which should’ve been mentioned as blindly reporting single studies without putting them in their larger context can be irresponsible and misleading.
I have focussed here just on the headline because far more people will read the headline than the article. The actual article is not amazing but it’s much better than the headline. I will also note that it’s probably the editor that wrote the headline and not the author of the article.