Medical research suggests that cannabis may help improve mood, but users also seem to suffer higher rates of depression.
Marijuana is sometimes referred to as ‘green Prozac’ due to the fact that many users find it helpful in lifting their spirits. But can it actually be an effective treatment for depression?
Interestingly, the idea that cannabis can be used to improve mood goes back hundreds of years. And many people today still agree.
“A lot of people report using cannabis effectively to treat depression,” says Zachary Walsh, an assistant professor of psychology at the University of British Columbia who heads a research lab focused on marijuana and mental health.
But whether cannabis has actually been proven to help with depression can’t be answered with a simple yes or no. The answer is more complicated because there are different types of depression, explains Walsh.
Generally speaking, depression is defined as the feeling of sadness or hopelessness over an extended period of time.
Studies on Marijuana and Depression
For depression that is caused by chronic stress, components of marijuana may be an effective treatment, according to a 2015 study by University of Buffalo scientists. The findings showed that stress caused a decrease in cannabis-like molecules naturally found in the brain, leading to behavior that mimicked depression.
Another study published in 2007 by a team at McGill University showed that administering low doses of THC could work like an antidepressant by increasing serotonin. However, in high dosages, THC decreased serotonin and seemed to worsen depression.
“These findings confirm what has been reported by people who smoke cannabis,” explains Dr. Gabriella Gobbi, who co-authored the McGill study. “Often it produces euphoria, calmness, sociability, but in other circumstances it can produce bad dreams and negative feelings.”
Overall there hasn’t been enough research in the field, Dr. Gobbi says, adding that the type of research needed to confirm whether marijuana can effectively treat depression is quite complex.
“Not only do we have to determine the dose-effect of cannabis on depressive people, but also which kind of cannabinoid may have a positive effect on mood.”
Cannabinoids are a class of molecules found in cannabis, which include THC and CBD. Over 60 different cannabinoids have been identified in marijuana, making it difficult to determine the drug’s overall effect on depression.
Higher Rates of Depression
While medical literature suggests that cannabis can improve mood, studies involving recreational users often show that people who use cannabis are more depressed, says Walsh.
“What those studies have noted is that they can’t really determine what comes first,” he explains. In other words: “Does cannabis cause depression? Do depressed people try to use cannabis to help with depression? Those are questions that are out there.”
An important factor in the answer could be the age of the person consuming cannabis.
According to research conducted by Dr. Gobbi in 2009, daily use of marijuana can cause depression and anxiety in teens.
“Cannabis, when consumed by adolescents, induces depression and anxiety later in adulthood, even if the people did not have any susceptibility for these mental diseases,” she says.
Cannabis vs. Antidepressants
While researchers can’t completely confirm if marijuana is effective for treating depression, Walsh points out that other medicines fall into the same problem.
He says that in some cases, typical antidepressants are no more effective than a placebo and have side effects that may be more severe than those of marijuana.
Dr. Gobbi explains that in order to declare a drug effective for a certain disease, it must go through different stages of clinical trials, which marijuana has not.
“If we want to take a rational approach about medicinal cannabis, we should go through systematic clinical studies and finally determine its efficacy in treating specific diseases and its safety compared to standard antidepressants,” she says.
Walsh agrees that further research should compare cannabis to commonly used antidepressants. “Then I think people can make the choice,” he concludes.