As the legalization of cannabis continues to expand across the United States and throughout the world, the risk of developing cannabis use disorder (CUD) will also continue to rise, as well. But what are the risks associated with CUD, and what steps can be taken to mitigate them?
This is what a recent study published in JAMA Psychiatry hopes to address as an international team of researchers led by the Aarhus University Hospital-Psychiatry in Denmark to examine a potential link between CUD and mental health disorders, such as depression and bipolar disorder.
For the study, the researchers conducted a population-based cohort study using register data of 6,651,765 Danes—50.3 percent women and 49.7 percent men—in an attempt to draw a connection between CUD and potential increased risks for developing bipolar disorder and psychotic/nonpsychotic unipolar depression.
The study’s findings indicated an increased risk between CUD and unipolar depression, psychotic unipolar depression, and nonpsychotic unipolar depression; bipolar disorder, to including psychotic and nonpsychotic bipolar disorder, in both men and women; and a greater risk for psychotic than nonpsychotic subtypes of bipolar disorder, but not unipolar depression.
"The study is the largest of its kind in the world, and our findings suggests that cannabis use disorder is also associated with an increased risk of developing depression and bipolar disorder,” said Oskar Hougaard Jefsen, who is a PhD student from the Department of Clinical Medicine at Aarhus University, and lead author of the study. “The results recommend caution when it comes to using cannabis. This applies to people with an increased risk of developing mental illness, and to politicians and other decision-makers who are discussing the possibilities of legalizing cannabis."
Study lead author, Oskar Hougaard Jefsen, who is a PhD student in the Department of Clinical Medicine at Aarhus University. (Credit: Simon Byrial Fischel)
However, Oskar Hougaard Jefsen is quick to note that despite the results, the study’s findings do not indicate definitive confirmation that CUD causes the mental health disorders examined in the study, only that there is a potential link between CUD and the associated mental health disorders.
According to the Centers for Disease Control and Prevention, CUD is defined as the inability to cease cannabis use despite it resulting in both social and health issues in their lives. Several studies have attempted to estimate the number of cannabis users afflicted with CUD (3 in 10), the statistical likelihood of developing an addiction to cannabis (10 percent), and the risk of developing CUD based on the age a user starts using cannabis (under 18).
What new discoveries will researchers make about CUD and mental health disorders in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!