Teen cannabis use tied to adult depression and suicidal thoughts in new study
Using marijuana as a teen may increase a person’s chance of developing depression as an adult, according to a new large-scale study published in the journal JAMA Psychiatry.
The study comes shortly after the introduction of legislation that would legalize recreational marijuana across the country and while cannabis remains the most popular drug for teens.
For the study, researchers from McGill and Oxford Universities analyzed data collected from 11 studies that included almost 24,000 teenagers. Their findings suggest that using marijuana once a week or more before the age of 18 is linked to a 37% higher risk of depression by the age of 32 compared to those who do not regularly use marijuana.
By extrapolating this data out, the researchers say around 400,000 cases of depression in the U.S. right now might be related to teen marijuana use.
“If you put everything together — animal studies, brain imaging studies, these types of meta-analyses where you study association — we have an indication at least that adolescents should be aware not to smoke cannabis,” said Gabriella Gobbi, a co-author of the study and professor of psychiatry at McGill University in Montreal.
The study also found a link between teen cannabis use and suicidal thoughts as an adult, however that link was significantly weaker. The team investigated a possible link with marijuana use and anxiety but found no such association.
It is notable that while teen usage remains high across the country, many states which have legalized medical or recreational marijuana have not seen significant increases in teen usage. Additionally, teen usage and sales to minors are still prohibited anywhere the substance is legally sold.
Still, the findings raise serious questions about the long-time effects of marijuana use on mental health that warrant further research.