Cannabis and Mental Health: It’s Complicated

As the countdown to legal Canadian cannabis ticks forward, there’s growing interest in cannabis’s medical potential when it comes to mental illness, something that affects one in five Canadians.

Are those with mental illness using cannabis to help with symptoms, or are they using it as a result of having a mental illness?

Given those stats, and the reality that, outside of tobacco and alcohol, cannabis is the most common psychoactive substance used among the general population, it’s inevitable that the potential overlap of cannabis and mental illness will lead to a spike in questions for doctors.

And yet, many patients share a similar experience: When they approach their doctors about the possibility of using cannabis to help with mental illness, the suggestion is strongly dismissed. Since cannabis has a long way to go before it shakes off the stigma of being an illicit drug, some perceive it as a chicken-or-egg conundrum among those who use it to treat mental illness. Are those with mental illness using it to help with symptoms, or are they using it as a result of having a mental illness?

Because research into this quandary is minimal and doctors are often unforthcoming, the evidence is largely anecdotal.

Toronto-based photographer and activist Andy Lee uses cannabis, along with talk therapy, to treat his depression and anxiety. He came to this balance after trying antidepressants, and deciding they weren’t effective for him.

Since his doctor made it clear he was against the idea of medicinal cannabis to treat mental illness, Lee found another practitioner who was comfortable prescribing it. “I know this is a touchy subject and taboo but this worked,” he says.

Lee is now involved in cannabis and mental health advocacy.

“I know this is a touchy subject but this worked.”

Even though he’s found treatment that works, he admits there are risks to overusing cannabis. “It’s a healing plant but it shouldn’t be abused and taken for granted,” he says. “It’s like antibiotics, the positive effects diminish the more your body gets used to it.”

Claire Gabereau relates. For years, the Vancouver-based costume designer would chronically smoke cannabis. When she was diagnosed with depression, anxiety, and borderline personality disorder, her doctor strongly discouraged her from consuming cannabis. Her psychiatrist, on the other hand, was more open-minded and never criticized Gabereau’s habits. But when an additional diagnosis determined she had substance-use disorder, she decided to go completely sober, rather than start antidepressants.

“I didn’t like [that my psychiatrist] was like ‘sobriety might be good for you, here’s a bunch of drugs,’” she says.

It’s been three months since Gabereau changed her habits and her depression and anxiety appear to have subsided. “I don’t want to go back to smoking it all the time because I’d definitely get paranoia and anxiety,” she says. “It can be used as a tool and medicine but since I’ve been abusing it for so long, it lost its value and purpose.”

Invaluable Research From Israel

Most scientists will agree that cannabis’s 100+ compounds, known as cannabinoids, have a clear effect on humans’ biology. But there are a lot of gaps in the research of the therapeutic role it can play when it comes to mental illness, especially in the US, where medical research is stifled by cannabis’s prohibitive designation as a schedule-I narcotic.

Shauli Lev-Ran (courtesy of the subject)

Shauli Lev-Ran  is an addiction psychiatrist based in Tel Aviv. He focuses on the psychiatric aspects of cannabis use and the interface between pain, psychiatric disorders, and risk of addition.

He regularly treats patients in his clinical practice with both psychiatric disorders and cannabis-use disorders. As legislation and regulations surrounding cannabis change across the US, Canada, and other countries, he started examining the connection between mental health and cannabis more deeply.

Despite his area of expertise, Lev-Ran admits he hasn’t found definitive answers when it comes to the chicken-or-egg theory of what comes first, mental illness or the dependency on cannabis. “It’s complex and there are a lot of methodical issues that confound our ability to get reasonable answers to these questions,” he says.

In 2013, Lev-Ran conducted a study through the Centre for Mental Health and Addictions in Toronto. Based on data collected by the National Institute for Alcoholism Abuse and Alcoholism, it was a cross-sectional study of more than 43,000 people—the largest epidemiological study on psychiatric disorders and substance use abuse. Lev-Ran found people with mental illnesses are over seven times more likely to use cannabis weekly than those without a mental illness.

More specifically, the study analyzed the difference between the rates of cannabis use and abuse amongst people with psychiatric disorders compared to those without. The research was based on the subjects’ number and types of psychiatric disorders and the intensity of their cannabis use, which Lev-Ran admits is challenging to quantify. Unlike alcohol, there are no standard doses with cannabis use.

Lev-Ran found people with mental illnesses are over seven times more likely to use cannabis weekly than those without a mental illness.

“We can talk about frequency and we can talk about dose, but they’re not standardized,” he says. “If I smoke two joints a day that are low in THC, it’s one thing, but if I smoke skunk or high potency and I smoke a large joint without tobacco as a filler, in both cases the dose seems like the same but they’re very different.”

Lev-Ran followed up with a meta-analysis, culled from thousands of existing studies, and found that those who use cannabis are at an increased risk for developing depression. However, he noticed many of the individual studies within the meta-analysis left out significant considerations, such as childhood upbringing and a family history of substance abuse.

Lev-Ran followed up with another study in 2016, which surveyed both cannabis users and non-users who had never suffered from depression. It set to understand if cannabis users who never experienced depression were at higher risk of suffering from an onset of the mental illness, compared to non-users. The study also analyzed data from the National Institute for Alcoholism Abuse and Alcoholism. This time, it followed up on 34,000 individuals who had taken part in the 2013 study.

Lev-Ran found that regardless of frequency (or infrequency) of use of cannabis, there was no difference between the rates of depression. Conversely, individuals with depression were at a higher risk to start using cannabis compared to those with no depression.

“One thing is to maybe say that cannabis isn’t very detrimental but it also shows that it isn’t very helpful.”

Next, Lev-Ran examined if cannabis works in favour for those with depression. He surveyed people with mental illness who used cannabis and those who didn’t and found very little difference between the two groups. It’s a conclusion that can be interpreted in two ways.

“One thing is to maybe say that cannabis isn’t very detrimental but it also shows that it isn’t very helpful,” he says, adding that the conclusion was only based on one study. “But this shows the line on how we explore these questions.”

What makes researching cannabis and its effect on mental illness challenging is that cannabis isn’t an all-encompassing substance. There are thousands of strains and hundreds of chemical compounds like cannabinoids and terpenes within the plant.

“It’s clear that we’re not talking about one uniform compound,” he says. “So lumping all cannabis users together is almost ridiculous.”

The research on psychotic disorders like bipolar or schizophrenia is more clear-cut. The consensus is that cannabis triggers such disorders and can lead to substantially worse outcomes. But risk for any disease or disorder is a combination of pre-disposition and exposure to risk factors. For people heritably predisposed to schizophrenia, using cannabis, particularly during adolescence, increases the risk of developing the mental illness.

PTSD Leads the Way

Zach Walsh spends a lot of time examining the ties between marijuana consumption, mental health, and addiction. As an associate professor of psychology at the University of British Columbia, he oversees the Therapeutic, Recreational, and Problematic Substance Use lab, which studies cannabis use for therapeutic and recreational purposes.

Walsh says the only way to really know if mental illness precedes cannabis use or the other way around would be to follow people from an early age. That’s because most people start using cannabis around the same time they would demonstrate signs of mental illness—in their mid to late teens.

Walsh says the strongest evidence from his lab on cannabis’ effectiveness is among patients who suffer from post-traumatic stress disorder.

“Say you started smoking at 14 and at 18 are diagnosed with depression. It’d be hard to say whether you were feeling little bits of depression and were dealing with it by smoking cannabis as a pre-depression syndrome,” he says.

Medical trials can help reveal whether people who have mental illnesses are better off using cannabis or not, but researchers are far from understanding much beyond that.

Walsh points to the stigma around cannabis, which is still illegal in most countries, and how it hinders the drug’s potential from being taken seriously as medicine. Since cannabis has been branded an illegal substance that’s often associated with criminality, people don’t associate it with relief from symptoms. That could take time to reverse.

“I think [cannabis] should be given a balanced assessment,” he says. “All [drugs] have risks and relative benefits. We just have this stigma around cannabis. We’re less critical of drugs that come from pharmaceutical.”

Walsh says the strongest evidence from his lab on cannabis’ effectiveness is among patients who suffer from post-traumatic stress disorder, particularly in reducing nightmares. This is especially relevant for Canada’s Department of Veterans Affairs (VAC) and the Department of National Defense (DND), which are also reviewing existing research on the use cannabis for medical purposes. VAC will cover the costs of medicinal cannabis—to a limit of three grams a day—for some veterans who suffer from PTSD.

In a statement to Leafly, a Veterans Affairs official wrote: “Recognizing that this is still an emerging practice and field of study, the Department wants to ensure that the specific direction of its research initiative undertaken with DND will have the greatest impact on strengthening evidence on the effects of marijuana on the health of Veterans.”

“All (drugs) have risks and relative benefits. We just have this stigma around cannabis. We’re less critical of drugs that come from pharmaceutical.”

Walsh suspects that future trials will focus on broader anxiety disorders, which are often treated with pharmaceuticals like Valium or Ativan.

“It’s worth looking at side by side because those drugs have side effects as well,” he says. “They can lead to tolerance and withdrawal.”

If patients with mental illnesses or anxiety disorders are going to try cannabis as a treatment, Walsh stresses the importance of self-reporting. Finding a strain that works could be likened to finding the right prescription and dosage if a patient were to go on anti-depressants or anti-anxiety medication. Sometimes it takes a few months of trial and error to find the medicine that helps. By closely monitoring how certain strains and doses feel, a patient will get a better sense of what’s effective and what isn’t.

“As adults we should be given the choice,” he says. “The harms of cannabis have been well-tested even if the benefits haven’t been. I think adults can go in and make sufficient choices about whether they want to use cannabis or not.”

You Can’t Argue With Results

Toronto resident Alexandra Charendoff fully agrees, despite regularly being discouraged from cannabis use by a number of health care practitioners. After being  diagnosed with borderline personality disorder, generalized anxiety disorder, and agoraphobia, Charendoff found cannabis was the most powerful and effective way to relieve the anxiety that paralyzed her when she had to leave the house.

“It was almost instantaneous,” she says. “I can actually function when I smoke weed. It’s the only thing that’s had any impact. When I take an Ativan, I just want to lie down and sleep.”

When she brought up the possibility with her doctor, “it was apparent he’d had this conversation multiple times before” but wasn’t in favour of going the medicinal-marijuana route. She wasn’t that surprised. Every time she’d been to the ER for treatment for an episode, doctors strongly railed against cannabis use, but never had any data to back up why. Charendoff felt their input was one-sided.

“They’ll say it’s not a good idea but there’s no room for conversation,” Charendoff says.

It’s likely the data on marijuana’s potential to treat symptoms of mental illness will spike once the drug is legalized in Canada, and more research is administered. Until then, doctors will continue fielding question about how cannabis can potentially help. If they don’t have answers, it’s likely that patients, like Lee and Charendoff, will continue to explore options themselves.

“I don’t think it’s going to cure my mental illness,” says Charendoff. “But it helps.”