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cannabis and mental health

Is There a Link Between Mental Illness and Cannabis Use?

Anna Rivera

Institute of Emerging Health Profession, Thomas Jefferson University

CSO52: Cannabis & Public Health

Professor Megan K. Reed, Ph.D., MHP

Assignment Due: 11/27/22

Is There a Link Between Mental Illness and Cannabis Use?

‘Tell Your Children: The Truth About Marijuana, Mental Illness, and Violence’ by Alex Berenson is full of opinions with not much accurate research to back them up. He rants about what’s wrong in this society and points fingers at black and brown people, blaming them for increased violence due to mental health issues perpetuated by cannabis consumption.

His points of view are reminiscent of Harry Anslinger’s days with his racist propaganda and promoting ignorance in newspapers, like this excerpt from The Salt Lake Tribune in 1913: “Marihuana is a shortcut to the insane asylum. Smoke marihuana cigarettes for a month and what was once your brain will be nothing but a storehouse for horrid specters''. (Reed Ph.D., MPH, 2022, #1). As mentioned in the Module 3 lecture, newspaper reports on cannabis consumption were aimed at brainwashing to keep people fearful and the information wasn’t backed up by solid data. Unfortunately, the masses believed this disinformation about cannabis being affiliated with crimes/violence, which only strengthened prohibition.

In a way, I understand him agreeing and believing inaccurate data, which is still floating around these days and mostly due to the limited research available. This outcome is due to the FDA not acknowledging/accepting cannabis as having medicinal benefits. Also, the Schedule 1 status doesn’t help either so researchers are restricted because of the DEA. Thankfully, there is private funding available to continue research.

Now, let’s review some work about mental illness associated with cannabis use. The National Institute of Health’s research report named, “Is there a link between marijuana use and psychiatric disorders”, proposed that smoking high-potency cannabis daily has the potential to increase the possibility of developing psychosis

Is There a Link Between Mental Illness and Cannabis Use?

almost five times as opposed to those who never consumed cannabis (Is There a Link Between Marijuana Use and Psychiatric Disorders?; 2020).

It also noted that the substance amount used, the age when consumers first used, and genetics are contributing factors that affect the relationship between teens and cannabis consumption. It concluded that the most compelling evidence associated with cannabis use and psychiatric disorders is in individuals with pre-existing conditions, genetics, or related susceptibility.

The article also mentioned that there has been a correlation between suicidal thoughts/ attempted suicide and teens that consume cannabis. Lastly, it indicated that cannabis has been previously linked to ‘amotivational syndrome’, which they define as ‘diminished or absent drive to engage in typically rewarding activities’. According to, they define it as ‘a psychiatric condition that is characterized by a change in an individual’s personality, emotions, and cognitive function’. This condition is currently considered a hypothesis due to the endocannabinoid system’s role in helping regulate our mood. It’s been theorized that the brain alters from early cannabis use, but more research needs to be executed to verify this link.

In 1942, the American Journal of Psychiatry released an article named, “The Psychiatric Aspects of Marihuana Intoxication”. It included observations about research achieved at Welfare Hospital in NYC, under the mayor’s Commission of Marihuana. The leading doctors were Dr. Allentuck and Dr. Bowman, which studied 77 subjects released from prison. They concluded that cannabis is a contributory cause of crime and permits anti-social tendencies. (The Psychiatric Aspects of Marihuana Intoxication, 2019)

Is There a Link Between Mental Illness and Cannabis Use?

They indicated their conclusions were confirmed about cannabis relaxing inhibitions and possibly contributing to concerning behavior. However, the editor of the paper kept stating that further investigation was needed and I’m glad that was mentioned.

Just like Alex Berenson, Dr. Bowman and Dr. Allentuck expressed opinions without much evidence, which can be harmful, especially when it comes to public health. Misconceptions and misinformation do have a negative impact on one’s mindset and unfortunately, that’s how fear-mongering starts in the media.

Another research was covered by National Academies on mental health, and according to them, the evidence alluded to cannabis consumption possibly increasing the risk of developing disorders such as schizophrenia, depression, social anxiety, and other psychoses. They also found the following:

Alternatively, in individuals with schizophrenia and other psychoses, a history of cannabis use may be linked to better performance on learning and memory tasks. Heavy cannabis users are more likely to report thoughts of suicide than non-users, and in individuals with bipolar disorder, near-daily cannabis users show increased symptoms of the disorder than non-users. (Health Effects of Marijuana and Cannabis-Derived Products Presented in New Report, 2017)

Lastly, the National Drug & Alcohol Research Centre in Sidney also supported similar findings. (Gates, 2016). According to them, there are two main factors associated with cannabis consumption:

  1. The age you start consuming, especially before 18 years old

Is There a Link Between Mental Illness and Cannabis Use?

The study mentioned it is a key stage for brain development and can negatively impact synaptic pruning, which they define aswhen old neural connections are deleted and the white matter development is affected, which is responsible for transmitting signals in the brain.’

  1. Consumption pattern

This is about the dosage, duration, and frequency, especially if the user consumes weekly at a minimum. The higher the dose, the more THC (tetrahydrocannabinol, the main psychoactive chemical component in cannabis) is being ingested. They claim it has an impact on certain parts of our brains involving regulating emotions.

Based on the findings compiled from all these articles, not much is concrete evidence and I understand due to the limitations of research. However, they all have a similar consensus and that helps get a basic understanding of the potential issues that can stem from extensive or elongated cannabis use.

My takeaway is to not start until you’re an adult and consume in moderation. If there are underlying mental issues, the user should take precautions and cautiously monitor their intake to avoid making their condition(s) worse.

Is There a Link Between Mental Illness and Cannabis Use?


Gates, P. (2016). Does cannabis cause mental illness? | NDARC - National Drug and Alcohol Research Centre. National Drug & Alcohol Research Centre. Retrieved November 13, 2022, from

Health Effects of Marijuana and Cannabis-Derived Products Presented in New Report. (2017, January 12). National Academies. Retrieved November 12, 2022, from

Is there a link between marijuana use and psychiatric disorders? (2020, July 2). National Institute on Drug Abuse. Retrieved November 12, 2022, from

The Psychiatric Aspects of Marihuana Intoxication. (2019, January 17). Jama Network Journal. Retrieved November 12, 2022, from

Reed Ph.D., MPH, M. K. (2022). Professor [Module 3 Lecture]. In The Past.

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