I’m concerned about the impact of cannabis on young people.
So are we. The evidence is pretty clear that heavy use of cannabis by adolescents has lasting consequences. The risks are highest in early adolescence and begin to tail away in the late teens.
Stats Canada (the counterpart to our own Statistics New Zealand) has been publishing great data on the legalisation experience, which is summarised in this recent before-and-after-legalisation report. Short version: since legalisation, overall use of cannabis in Canada has risen slightly (2%) – but that increase is entirely among people over 25, who are at least risk. Cannabis use by adolescents, on the other hand, has fallen by nearly half since legalisation. That’s why they legalised and it’s the kind of result we would expect to see here.
Late last year, a study by the US Centres for Diseases Control confirmed earlier research showing that youth use of cannabis has fallen in Colorado and other states which have legalised cannabis. Another study published last year found that cannabis legalisation and regulation in US states was associated with an 8% drop in the number of high schoolers who said they used marijuana in the last 30 days, and a 9% drop in the number who said they’d used at least 10 times in the last 30 days.
Another recent study, using national data for the US, found that the rate of adolescent admissions for Cannabis Use Disorder has declined more rapidly in Washington State and Colorado since legalisation, in comparison to non-legal states. It follows a similar study last year that also found a substantial national decline in Cannabis Use Disorder among teens. The authors of the second paper speculated that “as the cannabis market becomes increasingly regulated, better information about cannabis use risks may be available.”
In other words, bringing cannabis out into the light may be facilitating better choices.
It’s important to note that this sort of research is only possible because the US and Canada have excellent public heath data on drug use. New Zealand really doesn’t. But the Cannabis Legalisation and Control Bill would require that research to happen here.
Study by the US Centre for Disease Control
Montana State University Study by Professor Mark Anderson
US Drug Use and Health Yearly Report 2017