What We Know About Marijuana and Mental Health

A cartoon map shows marijuana and mental health

Marijuana is known the world over for its mind-altering properties. Any cannabis consumer worth their salt knows a good strong strain can completely shift your mood toward the positive, but how does cannabis affect mental health in the long run? Marijuana and mental health show some strong associations and correlations for better and worse, depending on the study. Read on to find out what we know about marijuana and mental health, in some of the most commonly asked-about categories.

An Inauspicious Starting Point

Any investigation of cannabis and its effects on mental health requires some historical context. Despite being a popular therapeutic and recreational agent through the past several millennia, cannabis got a terrible rap during most of the past century. The emergence of psychology as a service for regular people coincided with the smear campaign against cannabis. By the time of Sigmund Freud's death in 1939, the Marihuana Tax Act was in full swing, and the Federal Government was cracking down on cannabis in all its forms – including the versatile hemp.

One of the instrumental propaganda pieces of the 1930's paints an obscene picture of marijuana and mental health: Reefer Madness. Despite its 1936 release date, this absurd film depicts the devastating (and highly implausible) effects of marijuana on a group of teens.

Reefer madness caused a major stigma between marijuana and mental health. Older man has weed leaves in his eyes

In the film, we see the unfolding tragedy started by an unmarried couple selling weed to teenagers. Among the extraordinary misfortunes that befall the cast due to "reefer", here are some of the most ridiculous happenings:

  • A sordid affair
  • Pedestrian hit and run
  • Attempted sexual assault
  • An accidental (and fatal) shooting
  • An admission to an asylum for the criminally insane

As the main point reference for the majority of U.S. Americans, Reefer Madness doesn't exactly present a fair view of marijuana and mental health. In fact, it basically guarantees psychotic breaks from as little as one puff of the stuff.

Marijuana and Mental Health: Psychosis

So, how much bearing does Reefer Madness have on marijuana and mental health in real life? Very little. Even so, "marijuana psychosis" is an actual condition that crops up rarely. Cannabis-induced psychosis is, as you might guess, a collection of undesirable side effects resulting from consumption of marijuana. Many people, laymen and professionals alike, use this term freely. Unfortunately, it's quite misleading.

Psychosis is a condition in which "a person's thoughts and perceptions are disturbed" and they may lose touch with reality. A person experiencing a psychotic episode will experience paranoia, delusions and hallucinations, mood destabilization, and cognitive impairment. They may appear confused, and may hurt themselves or others in severe cases. The disconnect is semantic, but significant. Use of the terms "marijuana psychosis" and "cannabis-induced psychosis" firmly blame cannabis as the root cause of the issue. This creates the implication that cannabis itself was the root cause of an individual's psychosis, and suggests they would not have developed the condition had they not consumed marijuana.

In reality, you either are or aren't predisposed to psychosis based on your genetics. It is true that cannabis can be one of many triggers for psychosis, but it simply doesn't create the condition out of nothing. Cannabis may turn the key, but your genetics made the lock.

What About Schizophrenia?

One of the scariest questions on marijuana and mental health concerns schizophrenia. This long-term disorder involves the gradual breakdown between the crucial functions of cognition, behavior, and emotion, resulting in extreme inappropriate behavior and inability to recognize reality. It shares many characteristics with psychosis, but happens over the long term rather than occasional episodes.

There is clear evidence of a connection between cannabis and schizophrenia, although the exact nature of the relationship has stirred controversy. Recent evidence from Israel's Tel Aviv University (TAU) has shed more light on the situation, helping to clarify the role of cannabis in the development of schizophrenia.

Researchers conducted the study using a mouse model with two main groups. One group consisted of regular mice, and the other had mice with a mutated DISC-1 gene that made them more susceptible to schizophrenia. These groups broke down further into four variations. They looked at:

  • Normal mice exposed to THC
  • Normal mice without THC exposure
  • Susceptible mice exposed to THC
  • Susceptible mice without THC exposure

The idea behind the study was to mimic "a clinical picture of 'first episode schizophrenia", according to Dr. Ran Barzilay at TAU's Sackler School of Medicine. The researchers were interested in the schizophrenia, which becomes present in adolescents who consume cannabis.

Pills in one hand, weed in the other

A Semi-Comforting Conclusion

Over the course of the study, only the mice with the mutated DISC-1 gene displayed any schizophrenic developments when exposed to THC. This may confirm only those with a genetic predisposition to the disorder are in danger from the consumption of cannabis. For many of us, this added proof may come as a relief. However, it also means adolescents and young adults with a family history of mental illness may be at risk if they begin experimenting with cannabis.

One compound of note in the study is brain-derived neurotrophic factor (BDNF), a protective factor at work in the brain's hippocampus. When susceptible mice received BDNF, THC stopped producing schizophrenia-related psychiatric events, making it clear that genetic predisposition is the key factor in whether cannabis may cause problems.

Weed and Anxiety

When it comes to marijuana and mental health, anxiety is a topic at the forefront of many minds. Most people have experienced anxiety in some form, and many even find cannabis to be a helpful way to relax and calm overactive nerves. Many strains, indicas in particular, get labels like "relax," "restore," and "unwind," specifically because of the calming effect they're meant to confer. For many, these labels are more or less accurate and cannabis does lessen their immediate symptoms of anxiety – but what about the people who report nothing but bad trips from weed?

Sometimes pure over-stimulation can lead someone to experience anxiety from weed. If you consume too much marijuana, you may feel something akin to sensory overload and not know how to handle it. But there are also people who experience severe anxiety each and every time they try to consume cannabis, and there may be a neurochemical reason why.

When THC enters the brain and binds to the endocannabinoid system's (ECS) receptors, it triggers the release of serotonin, dopamine, and a neurotransmitter called gamma-aminobutryric acid (GABA). GABA and serotonin can inhibit the firing of neurons that signal production of norepinephrine. Norepinephrine is a key chemical in keeping you alert and potentially anxious, so THC usually calms people down. But for some very unlucky people, the THC-induced lack of norepinephrine causes the brain to compensate in other locations related to agitation and excitation. Once that happens, they're hit with an accelerated heartbeat and spike in stress-causing cortisol.

Weed and Depression

Depression is a common reason to self-medicate with cannabis throughout history. The body's endocannabinoid system regulates crucial mood-stabilizing chemicals like serotonin and dopamine, both of which are lacking in people who have depression. Evidence suggests marijuana can stimulate the ECS to produce more beneficial compounds, and restore a healthy balance of chemicals. One study from California State University at Long Beach concludes "Those who consume marijuana occasionally or even daily have lower levels of depressive symptoms than those who have never tried marijuana."

Anecdotal evidence certainly suggests some strains can help treat symptoms of depression in the short term. A few other studies, however, point to a correlation between marijuana and mental health in the form of increased depression. No study has yet clarified whether smoking weed causes depression, or whether being depressed causes sufferers to smoke more weed. Common sense and a familiarity with the uplifting effects of cannabis lead me to say that I firmly suspect it's the latter.

Cannabis Use Disorder

Marijuana and mental health can and do coexist happily in the lives of many. But when cannabis becomes a crutch, mood disorders can worsen, and dependency can sneak into play. Daily consumption of any substance can lead to addiction of sorts, even if it's relatively mild. Most of us know someone we don't dare speak to before their first four cups of coffee, and weed can be the same way.

marijuana in a prescription bottle

Self-medicating daily without regard to an increase in tolerance does lead to dependence. Although only about nine percent of people who try cannabis develop a dependence, it can be a troublesome hobby to quit. There are withdrawal symptoms for those who quit marijuana after heavy consumption, and they're mildly annoying. Trouble sleeping, intense nightmares, lack of appetite, and irritability are all possible symptoms, and they are sure to exacerbate any mental health issues an individual is experiencing.

As with any other medicine, overuse decreases efficacy and can alter your body's stable processes to accommodate the constantly-present substance. Moderation is key to maintain a healthy balance between consuming marijuana and mental health.

The CBD Connection

Unlike cannabis in its natural form, CBD is almost universally acknowledged to provide positive therapeutic benefits with little to no downside or potential for dependency. In fact, CBD may be able to help people beat addiction to dangerous substances like heroin and alcohol. It may also help mental health by acting as an antipsychotic.

High-CBD strains can be an excellent way to lessen the impact of anxiety and depression, thanks to varying ratios of CBD to THC. Microdosing CBD oil can be a smart move for those who want the benefits of cannabis but don't want it to directly alter their mood. The lack of psychoactivity is also ideal for those who know they have a history of psychological disorders.

The Bottom Line

Marijuana and mental health aren't mutually exclusive, and weed will not make you go crazy unless you're predisposed to mental disorders in the first place. Cannabis can help mood disorders and anxiety when used in moderation, but heavy, long-term use can morph into addiction and worsen any conditions you have in the first place. Responsible adult use of marijuana should pose no danger for most people.