VANCOUVER – A 20-year study from Britain looking into the health risks of cannabis finds that smoking pot is far from harmless.
The study, published in the journal Addiction, finds regular use of the drug by teens impairs intellectual development and doubles the risk of developing psychotic disorders, including schizophrenia.
It also finds there is strong evidence regular pot use leads to the use of other drugs.
“Marijuana is just not the same benign substance that we knew about in the 60s,” says Kerrie Watt from Coastal Health. “It does have real health impacts and impacts in the lives of young people and their families in particular, and it’s something worth taking a look at.”
“Particularly in adolescents, the memory centres of the brain appear to shrink and that they are impaired in terms of their ability to learn and have good recalls of memories.”
Dr. Wayne Hall, who conducted the study, came to some of the following conclusions:
- Regular cannabis users can develop a dependence syndrome, the risks of which are around one in 10 of all cannabis users and one in six among those who start in adolescence.
- Regular cannabis users double their risks of experiencing psychotic symptoms and disorders, especially if they have a personal or family history of psychotic disorders, and if they start using cannabis in their mid-teens.
- Regular adolescent cannabis users have lower educational attainment than non-using peers but we don’t know whether the link is causal.
- Driving while cannabis-intoxicated doubles the risk of a car crash; this risk increases substantially if users are also alcohol-intoxicated.
A regular cannabis user refers to someone who gets high at least three times a week.
But Dana Larsen from Sensible BC says the study actually shows how remarkably safe marijuana is for people. “If you put those numbers in context compared to alcohol or other things, you see that marijuana is actually remarkably safe and that’s what this study really confirms,” he says.
“Every parent wants the best for their children and doesn’t want to see their kids having any problems, you know, for people that use cannabis about 90 per cent don’t have any problems.”
Larsen adds that no one is calling for legalization of marijuana for teenagers and that the best way to keep it out of young peoples’ hands is to legalize it for adults.
SFU criminology professor Neil Boyd says none of this is relevant to the debate about whether marijuana should be legalized. “But in terms of public health there has long been this notion that marijuana is relatively harmless and you can’t really become dependent on it and I think neither of those things are true.”