Researchers in the UK and Canada said they have found evidence showing that the use of cannabis in adolescence makes one more likely to develop depression later in life.
The study, which was published in the journal JAMA Psychology, suggests that the use of marijuana among teens increases their risk of developing depression in adulthood by 37 percent.
According to the researchers, their findings should serve as a warning to families who consider smoking weed as a normal part of the growing-up process. They explained that this is because the developing brain is particularly susceptible.
The researchers from Oxford University in the UK and from McGill University in Montreal said that cannabis use among young people was an important public health issue. This is particularly true given that the cannabis available now tends to be stronger than the cannabis that was available previously.
In England and Wales, around one in every nine teens and young adults use cannabis each year. Prof. Andrea Cipriani noted that some parents have a more relaxed attitude towards the drug.
She said that their new finding is important information for both teens and their parents. This is because, while the risk is modest, it can still have a devastating effect.
The risk of using cannabis
The research team looked at 11 past studies, which covered more than 23,000 young people. Those who had already displayed signs of depression or had a family history of the illness were not included in the study.
The researchers found that cannabis use among young people before they reach 18 years old increased by 37 percent their chance of developing depression in young adulthood, which is before the age of 35.
This means that around one in every 14 cases of depression in people belonging to this age group could be attributed to cannabis use in their teenage years. This number translates to 60,000 young adults in the UK!
The study also looked at whether cannabis use is associated with anxiety and suicide attempts, too. And it found that there was an increased risk of anxiety in young adulthood, although it was not statistically significant.
Meanwhile, those who used cannabis as teenagers were three times more likely to commit suicide. The data on this trend, however, was not deemed robust enough to draw a firm conclusion.
What do the study’s findings mean?
The findings of this particular study cannot be considered proof that cannabis consumption definitely causes depression. Instead, researchers can only say their findings looked to be a strong link.
In order to prove the link between teenage cannabis consumption and depression with absolute certainly, clinical trials would have to be conducted. And these trials will probably never be done as they are unethical.
According to Prof. Sir Robin Murray, a psychiatrist at King’s College London, the research can’t be considered conclusive. He also noted that it was likely that any risk would be down to the amount and potency of cannabis consumed, which is something that the study was not able to find out.