Evidence lacking that marijuana products improve mental health

(Photo from Cleveland Clinic)

We’ve heard a lot lately about medicinal marijuana and marijuana-derived products for mental health, but do they work?

According to a new study – the evidence is lacking.

Cleveland Clinic’s Brian Barnett did not take part in the study, but said using medicinal marijuana, or related products, to treat mental health conditions cannot be justified based on current research.  

“There was pretty low-grade evidence for marijuana for treatment of anxiety disorders,” Barnett said. “It also looked at the use of marijuana for the treatment of other psychiatric disorders and found no compelling evidence at this point that marijuana, or any of its derivatives, are effective treatments for things such as depression, ADHD, Tourette syndrome or post-traumatic stress disorder.” 

Researchers reviewed 83 studies looking at medicinal marijuana, synthetic marijuana and marijuana-derived products.

They studied the products’ impact on six mental health conditions -- depression, anxiety, attention-deficit hyperactivity disorder (ADHD), Tourette syndrome, post-traumatic stress disorder, and psychosis.

The study did not find compelling evidence for using any type of marijuana for mental health treatment. 

The authors noted the studies reviewed were small and low-quality. 

Dr. Barnett believes high-quality research is needed to determine whether marijuana and related products are effective, and safe, to treat mental health problems. 

In the meantime, he said people should be aware of the known risks associated with marijuana. 

“Although we don’t know a lot about the potential health benefits, we do know about risks which include addiction,” Barnett said. “We’ve seen increases in the numbers of individuals coming to the emergency room as marijuana is becoming legalized in various contexts. We also know marijuana is becoming stronger, in terms of THC content, than it was in the past which can make for more adverse reactions.” 

Barnett said it’s important to talk to a doctor before self-treating with marijuana, or products derived from marijuana because there are certain conditions and medications it can interact with.

Complete results can be found online in The Lancet Psychiatry journal.