Marijuana: Medicine for Some, Poison for Others

From January 2024

According to a study published in Lancet Psychiatry cannabis use early in life impacts the later diagnosis of psychosis among vulnerable individuals. Chronic cannabis use, more than twice per week, is claimed to be consistently associated with the onset of various mental health disorders while use more frequent than twice per week has been determined to be associated with 4 times the risk of psychosis, schizophrenia and bipolar disorder in particular among those predisposed.

Each ailment has a strong genetic component -including a  30 times greater likelihood of developing bipolar if a first relative has it- but individuals prone to any form of psychosis are at greater risk of instigating their first episode after regularly consuming marijuana.

This study is the first systematic review of the association of cannabis potency and psychosis. Overall the data indicates the more potent the THC concentration the higher probability of causing the expression of lasting psychosis disorder later in life.

The study compared the odds of psychotic disorder among the general population compared to those who have been admitted to hospital for a psychotic disorder for the first time. All parties were asked about their use of marijuana as well as the potency of what they consume.

Before proceeding it is key to note the primary factors of psychotic disorders stem from differences in brain development as well as genetic risks. Such disorders typically become apparent between the ages 18 and 25 but may present themselves as early as childhood or as late as 40 years old. While marijuana can influence temporary states of psychosis it cannot in and of itself create the biological elements of psychotic disorders.

The study collected data of individuals between 18 and 64 years who ended up in psychiatric services in 11 sites across Europe and Brazil with their first episode of psychosis. The individuals were assessed by whether they consumed cannabis and whether what they consumed had a high concentration of THC (greater than 10 per cent) or low concentration (lower than 10 per cent).

The study showed that across the sample of over 1,000 willing participants 20.4 per cent indicated daily use of cannabis, 12.2 per cent self reported the use of high potency cannabis. The highest rate of marijuana consumption among those admitted to psychiatric care was seen in Amsterdam where 43 per cent of participants reported using marijuana daily, most of which was high potency.

“In the context of the well reviewed epidemiological and biological evidence of a causal link between heavy cannabis use and psychotic disorders, our findings have substantial implications for mental health services and public health,” the researchers reported. “Education is needed to inform the public about the mental health hazards of regular use of high-potency cannabis, which is becoming increasingly available worldwide.”

The study found that daily, chronic use of cannabis is associated with a greater than three times increased risk of developing psychotic disorder compared to those in the general public who have never consumed. The study determined the risk of a psychotic episode increased nearly 5 fold if high-potency marijuana is consumed.

These results are a cause for concern in Canada as marijuana has been legal since October 2018. The legalization has created a massive market of marijuana growers and storefronts selling an array of products.

According to a Canadian Tobacco, Alcohol and Drugs Survey conducted in 2015 and available via Stats Canada, 28.4 per cent of 18 to 24 year olds had consumed cannabis in the past year they were surveyed.  A survey by the Canadian Centre on Substance Use and Addiction (CCSUA) conducted in 2022 showed that 37 per cent of Canadians between 16 and 19 years old reported having consumed marijuana while 50 per cent of those between 20 and 24 years old reported the same.

Data from CCSUA indicates that the overall increase of marijuana consumption among Canadians 16 years and older was approximately 27 per cent, a 2 per cent increase from 2021. The age range with the largest increase in that time frame was 25 years and older which grew from 22 per cent in 2021 to 25 per cent in 2022.

With the advent of new strains of cannabis as well as the engineering of high potency cannabis the potential harm individuals may unknowingly cause themselves has increased as well. With this ease of access there should be a collective assessment of consumption among anyone under the age of 25.

The potential lasting effects on the brain differ for someone who is using cannabis over the age of 25 than it is for someone under 25. Whether they are consuming edible marijuana, smoking or vaping, a person under 25 is at greater risk of long lasting alterations to the development of their brain as a result of high marijuana consumption as the brain continues to develop until the age of 25.

The development of a healthy brain, and a healthy mind, relies on the fine tuned neuro circuitry. The last portion of the brain to develop is the frontal lobe which is responsible for decision making and judgement among other things. Of course these concerns increase even more so as the age of consumption decreases. The overall developmental impact in these instances depends on the frequency of consumption as well as the potency of the marijuana itself.

Most people starting to use cannabis in Canada are between 16 and 24. The general perception of cannabis is the health benefits associated with it. By taking this narrow approach young people are misinformed of the severe detriments which may await them later in life with the consumption of high potency cannabis.

The government of Canada website reports that 1 in 3 Canadians who use marijuana will develop a problem with their consumption habits and that 9 per cent of those who use cannabis will develop an addiction. It is second to alcohol as the most used substance in Canada.

Since becoming legal in 2018 the Canadian marijuana industry has bloomed, reportedly valued at $10.8 billion in 2023. Stores have sprung up in every city across the country, with some within a short walk of each other. While we continue into the new era of legalized marijuana it is still crucial to understand that it comes with strings attached. While we all know the cliché of a bad memory, frequent consumption of marijuana can cause increased anxiety and puts some at risk of depression. For others it decreases these factors. Ultimately it is a product with both good and bad attributes which vary from person to person.

Marijuana is useful in some fields of medicine from pain relief to relieving nausea for individuals undergoing chemotherapy. While it is medicine for some but a poison for others. As with any substance it is crucial to keep an honest perspective of this substance. What was for so long illegal has been given new life in Canada but with this comes the responsibility of properly informing ourselves and young people of the risks that come with consumption. We are passed the days of propaganda films and advertisements telling of how we’ll lose our whole lives in a single puff, but the age of information allows us to see the full picture.