How does cannabis impact mental health?

Working in family medicine for more than 20 years, Dr. Mark Ware has long witnessed the therapeutic benefits of cannabis, not only to address physical pain and discomfort, but also to treat mental health.

Many of Dr. Ware’s patients have chronic pain and have exhausted conventional therapies. Cannabis, in some cases, has helped not only to manage their pain, but also to alleviate the accompanying stress and anxiety.

“It was obvious to me very early on that cannabis had a very broad effect on people’s health, including their mental health,” Dr. Ware, chief medical officer for Canopy Growth, told The GrowthOp. “Cannabis and mental health are intimately intertwined.”

It’s a relationship, however, that is just starting to be understood.

Cannabis is not a singular compound; there are more than 100 cannabinoids in the plant that can produce different, sometimes opposing, effects. Add to that that every person has an individual endocannabinoid system that responds differently to those compounds.

Health Canada warns that individuals with a personal or family history of mental illness might be vulnerable to negative mental health outcomes associated with cannabis use. Beyond medical and psychological background, the dose and method of consumption are other factors to consider, Dr. Ware says.

“It’s a complex topic. And it’s very difficult to distill it down to simple messages,” he says. “Cannabis and cannabinoids may have therapeutic properties, but they may also have risks. And it’s really important that people acknowledge, talk about and inform themselves about what they’re doing.”

The two cannabinoids that get the most attention, cannabidiol (CBD) and tetrahydrocannabinol (THC), can also lead to very different mental health outcomes. CBD has demonstrated potential in treating anxiety-related disorders, psychosis and schizophrenia, while THC can have adverse psychological effects, especially in high doses. On the other hand, THC can also provide therapeutic benefits.

There’s also much more at play than just THC and CBD. Cannabis plants also contain hundreds of terpenes, some of which are believed to have positive impacts on mental health. Limonene, which is found in citrus fruits, may help combat depression, anxiety and stress. Linalool, found in lavender, could help reduce anxiety.

How the terpenes and cannabinoids intertwine and work together, especially in the context of anxiety and mood disorders, is an ongoing topic of research.

“There’s still a vast amount of knowledge about cannabis and cannabinoids that we have yet to discover,” Dr. Ware says.

As Canada approaches two years of legalization, and other countries start to rethink their approach to cannabis, research is proliferating, especially in regards to CBD, which has shown promise for treating a range of psychiatric disorders.

Legalization has helped change the conversation about cannabis and mental health, Dr. Ware says.

“People have gone from thinking of cannabis as a drug, which is very detrimental to mental health, causing psychosis and mental illness and being associated with substance abuse and addiction, to the world where we’re actually thinking of cannabis as having positive effects and potentially therapeutic benefits,” he says. “It’s really been a remarkable transformation.”