Marijuana Use and Its Impact on Mental Health

As marijuana legalization continues to spread worldwide, questions remain about its potential negative effects on mental health, both in the short and long term. Even in countries where marijuana and its active components have been legal for some time, experts cannot say with certainty that marijuana use does not trigger symptoms of latent psychological disorders in certain groups, or cause delayed negative effects that may only become apparent years later, especially in older users.

While many independent studies claim marijuana can be effective in treating and managing symptoms of mental illnesses, most findings (except for PTSD and depression therapy) have not yet been confirmed in clinical trials. Notably, aside from coffee and tobacco, marijuana is the most widely used psychoactive substance in the world, surpassing alcohol and many illegal drugs. Given this, even in regions where it is legal, authorities and healthcare professionals strictly regulate access to marijuana to prevent therapeutic products from being diverted for recreational use and to minimize the risks of chronic use among the population.

In such circumstances, doctors are often very cautious about issuing recommendations or prescriptions for marijuana, especially for patients interested in using it for mental health therapy, believing that this form of treatment may be too risky and unjustifiably ineffective. Even in regions where laws specifically allow marijuana for conditions like autism, schizophrenia, or PTSD, many doctors remain skeptical due to a lack of convincing evidence of safety and efficacy, and because much of the perceived link between marijuana use and psychological disorders is anecdotal.

Personal Experiences with Marijuana for Mental Health

What do people who use marijuana for self-treatment of neurological disorders, and the doctors who specialize in this practice, have to say? Is marijuana more harmful than helpful for treating stress and depressive disorders, or is it an overlooked remedy for conditions still considered incurable? As is often the case, the answer is complex.

Andy Lee, a professional photographer and cannabis activist from Toronto, has advocated for therapeutic marijuana use for years, especially to enhance the effects of psychotherapy. Andy has struggled with anxiety and seasonal depression, using talk therapy and regular marijuana or extract consumption to calm his nerves. About five years ago, after a negative experience with pharmaceutical antidepressants, he began using marijuana as medicine. When his doctor refused to consider marijuana as an alternative, Andy found another therapist who was more open to its use. “When I first considered using marijuana for panic attacks and depression, the topic was mostly taboo among doctors. But I found a therapist willing to try, and I was happy with the results,” Andy says. Since then, he has been active in the national movement supporting marijuana legalization for mental health therapy, believing that with proper control and caution, cannabinoids could be used to treat a wide range of conditions.

Andy acknowledges that frequent marijuana use can cause psychological dependence in some people, recognizing the risks of both recreational and therapeutic use. “Like any medicine, marijuana should be used appropriately and in moderation to minimize risks,” he notes. “Also, moderate use helps maintain its beneficial effects longer. Cannabinoids are a lot like antibiotics: the more you use them, the less effective they become.”

Another advocate, Claire Gabro, a clothing designer from Vancouver, agrees with Andy. She regularly smokes marijuana for therapeutic purposes to manage depression, stress, and mood swings associated with borderline personality disorder. Like Andy, Claire faced resistance from therapists when she expressed interest in marijuana treatment. Eventually, one therapist allowed her to use marijuana experimentally. After about three months, the doctor suspected Claire had developed psychological dependence due to increased use and suggested she abstain for a few months or switch to antidepressants. Having had negative experiences with those medications, Claire chose temporary abstinence. “It’s funny that after blaming marijuana for dependence, the doctor immediately suggested other, more dangerous psychoactive drugs. I decided to take a break from marijuana and then regulate my use,” she says. After several months of abstinence, with only mild and infrequent relapses of panic and mood swings, Claire resumed marijuana use in smaller doses, increasing its benefits and reducing the risk of side effects and dependence. “My current, more measured routine is much more practical than smoking whenever I’m stressed,” she says. “I use less product and get more benefit—energy and focus for work and creativity, not just distraction or dealing with overdose effects. Previously, I sometimes used so much that it actually worsened my symptoms. My advice: use marijuana in moderation, or it will lose its benefits and only cause discomfort, both physical and psychological. And if you feel it’s making things worse, stop before it gets out of hand.”

Insights from Israeli Researchers

Researchers confirm that marijuana contains about a hundred active cannabinoids, in addition to the well-known THC and CBD. However, there is still no consensus on how most of these substances affect the body and mind. Some scientists even question the well-studied effects of THC and CBD, suggesting that their therapeutic properties may depend on their combination with other cannabinoids or terpenes, whose effects are often overlooked due to low concentrations.

Few countries allow free research into marijuana and its active compounds. Israel is a global leader in medical marijuana research. Dr. Raphael Mechoulam, working in Israel, discovered the structure and functions of THC and CBD, their connection to the body’s endocannabinoid system, and synthesized many other cannabinoids.

Israeli doctors and psychologists are also leaders in studying the link between marijuana use and the progression or remission of psychological disorders. Dr. Shauli Lev-Ran, a psychologist specializing in cognitive therapy for addictive behaviors, is one such expert. He studies the relationship between marijuana use and the risk of latent psychological disorders and possible psychological dependence. Dr. Lev-Ran regularly encounters both successful therapeutic use and cases where marijuana triggers previously hidden disorders or strong psychological dependence, in both recreational and therapeutic users. He expects that as legalization expands, incidents of latent psychological disorders and dependence will rise globally.

Despite his experience, Dr. Lev-Ran and his colleagues cannot definitively judge the safety and justification of marijuana as an alternative treatment for mental disorders. They also have not identified the exact mechanisms or causes of psychological dependence, as it appears only in a narrow group of people, regardless of frequency or dosage. “After more than 10 years of practice, these issues remain a medical version of the chicken-and-egg problem,” he says. “We have plenty of observational data, but the sheer number of factors makes it hard to analyze and systematize the effects of each cannabinoid, let alone the entourage effect of all compounds present in marijuana extracts.”

To support the hypothesis that people with emotional and psychological disorders may subconsciously turn to marijuana for its perceived positive effects, Dr. Lev-Ran cites a 2013 study from Toronto’s Center for Addiction and Mental Health. The study analyzed over 43,000 patient records to find patterns in marijuana use and mental health. It found that people diagnosed with severe psychological disorders used marijuana about seven times more often per week than those without such diagnoses. However, the study could not determine whether marijuana use was a cause or effect of these conditions.

Another cross-analysis from the American Center for Addiction and Alcoholism in 2016 showed similar results. While there was a slightly higher risk of worsening mental illness among regular marijuana users, people with diagnosed psychological disorders did not use marijuana more often than the general population. Dr. Lev-Ran concluded that people prone to depression may be more likely to use marijuana due to its psychological effects, but the data does not clarify whether depression is a result of chronic marijuana use or vice versa.

“Overall, these reviews suggest that marijuana may have beneficial properties for treating or at least modulating symptoms of depressive and stress-related disorders. However, these effects may be short-term and minor, as most patients continued to experience symptoms despite self-medicating with marijuana,” Dr. Lev-Ran says. “The data highlight the contradictions in cannabinoid effects, due to their complex nature and interactions with many other substances. For some, marijuana helps with stress and depression without causing dependence or side effects; for others, even small amounts cause problems. Despite progress in cannabinoid research, I would not rely solely on marijuana as a treatment for such disorders, nor use black-market products without consulting a specialist. While cannabinoids are safer than many other psychoactive substances, it’s too early to say they are completely safe for mental health therapy. The risk of negative and irreversible reactions remains significant.”

Dr. Lev-Ran also notes that the effects of cannabinoids on stress and depressive disorders are still unclear, but studies on borderline personality disorder and schizophrenia show that cannabinoids usually worsen symptoms in most patients. “Except for rare documented cases, cannabinoids had a negative effect on people with schizophrenia or borderline disorders, worsening both negative and positive symptoms and negatively impacting emotional and psychological health,” he says. “Even a single use by people with a genetic predisposition to these disorders can significantly increase the risk of developing them, especially hereditary forms of schizophrenia.”

Cannabinoids in PTSD Therapy

Canadian doctor Zach Walsh, an expert in the relationship between marijuana use and psychological disorders, agrees with his Israeli colleague about the complexity and lack of understanding of how cannabinoids affect mental health. Dr. Walsh, head of a lab at the University of British Columbia studying the effects of psychoactive substances on mental health, says it’s only possible to determine whether marijuana use is a cause or effect of disorders like depression or stress by knowing each patient’s history in detail. Often, psychological illnesses are diagnosed only in late adolescence, years after individuals first try marijuana, alcohol, tobacco, or other substances, making it hard to establish causality.

“For example, if someone started using marijuana at 14 and was diagnosed with chronic depression at 18, how can we know if the habit caused the illness or was an early sign of it?” Dr. Walsh asks. “As Dr. Lev-Ran noted, such habits may be early warning signs of more serious disorders.”

Dr. Walsh also points out that the stigma around marijuana as a “narcotic” influences perceptions of its risks more than its actual effects. “Most studies show that the majority of users never develop mental health issues, learning problems, or emotional regulation difficulties. Yet, the public and even doctors often assume marijuana is harmful simply because it’s still widely considered a ‘drug,’ ignoring its proven therapeutic properties,” he says. “Unlike pharmaceuticals, which are also psychoactive and often have stronger side effects, marijuana is still unfairly blamed for negative effects.”

As evidence of marijuana’s effectiveness for mental health, Dr. Walsh cites its use in treating PTSD. This area of cannabis medicine is supported by numerous studies, thousands of patient testimonials, and a growing number of clinical trials, including projects by the US National Institutes of Health and Canada’s Veterans Affairs Ministry. Unlike the US, Canada fully supports research into marijuana’s therapeutic properties for veterans. The country, the second in the world to fully legalize marijuana, formally allows its use for PTSD under medical supervision and continues to study its effects.

Given the success of these trials, Dr. Walsh believes Canada’s Ministry of Defense will soon fund research into other uses of marijuana for veterans’ mental health. “Currently, stress-related conditions like anxiety and chronic stress are the second most common veteran diagnoses after PTSD. These are now managed with pharmaceuticals like Valium or Ativan, which can have more severe side effects and higher risk of tolerance than marijuana,” he says. “Marijuana is less likely to cause tolerance and side effects.”

Dr. Walsh emphasizes that the therapeutic effect of cannabis depends on dosage and the concentration of active compounds. “Not every marijuana strain—meaning the combination of THC, CBD, and other cannabinoids—has the same effect on PTSD patients,” he notes. “Like other medications, the effectiveness and safety of marijuana depend on the specific ratio and concentration of cannabinoids, which doctors and patients must determine by trial and error. In the absence of large clinical trials, a practical approach would be to create a database of effective dosages and methods, filled in by doctors and patients, to identify the best options for different categories of users.”

“Given the relatively harmless nature of the plant, I believe every adult, especially those with PTSD, depression, or stress disorders who haven’t found relief with other treatments, should have the right to try marijuana as an alternative medicine,” Dr. Walsh says. “While there are risks, they are not enough to justify banning cannabis psychotherapy or controlled research into its potential as a medicine.”

Real-World Results

Many people who self-medicate for mental health issues agree with these experts, often having started such practices long before legalization. One such person is Alexandra Charendoff from Toronto, who has used therapeutic marijuana for several years to manage mood swings related to borderline personality disorder. Suffering from chronic anxiety, agoraphobia, and mood swings since adolescence, Alexandra says that unlike pharmaceutical tranquilizers, marijuana has a noticeable positive and lasting effect on her emotional state and thinking, rather than just dulling her central nervous system.

“The effect of marijuana is felt within minutes, unlike antidepressants, which can take days or weeks to work,” she says. “Cannabinoids really help me control harmful impulses and negative thoughts while staying active and functional, not just making me tired and sleepy like Xanax or other tranquilizers that every therapist seems to recommend.”

Alexandra also faced resistance from therapists before deciding to self-medicate with marijuana. “Doctors automatically react negatively to requests for marijuana for mental health treatment,” she notes. “Even after repeated ER visits and failed treatments, my doctors refused to authorize marijuana for borderline disorder, citing a lack of data on its safety. Despite my personal success and that of others, doctors dismissed the evidence as ‘happy coincidences.’ The very idea of using marijuana this way is still taboo for many doctors.”

“I wouldn’t call marijuana a cure for my disorder. After years of use, I can’t say my episodes are less frequent or severe,” Alexandra adds. “But a few puffs from a joint or vaporizer instantly calm my nerves and stabilize my mood. Marijuana just helps me function in society with my condition and not feel sick or crazy, which I can’t say about many pharmaceuticals. For many people, that’s more than enough.”

Original author: Elianna Lev