Is It Plausible?
We do not know for certain whether or not marijuana use can result in the death of brain cells. There is a need for additional studies to determine whether or not the various methods of consumption, such as smoking, electronic cigarettes, and consuming edibles, each have a unique impact on the general health of the human brain. Ongoing research is looking into the effects that chronic marijuana use has on a person’s cognitive abilities. The following is the state of our knowledge concerning the effects that marijuana has on the brain.
Consider the Infamous Test to Measure Intelligence
A well-known study that was conducted in New Zealand in 2012 looked at the relationship between cannabis use and cognitive skills in over 1,000 people over a period of 38 years. The researchers found a correlation between the long-term use of marijuana and a decline in cognitive function.
In particular, they came to the conclusion that:
- People who began heavy cannabis use as adolescents and continued it into adulthood experienced an average IQ drop of between six and eight points by the time they entered the middle of their lives.
- People who had previously used cannabis but had stopped doing so as adults did not regain any of the IQ points they had lost.
- There was no correlation between heavy cannabis use and a decrease in IQ in adults who began using cannabis later in life.
Several factors contributed to the significance of the impact of this study.
To begin, this was one of the earliest large longitudinal (long-term) studies to investigate the relationship between cannabis use and mental function. Next, the findings imply that the use of marijuana during the teenage years may have an effect that is permanently detrimental to the growth of the brain in adolescents. This conclusion is supported by a few additional pieces of research. Nevertheless, the New Zealand analysis does have a number of significant shortcomings. It is not possible to conclude that using cannabis leads to lower intellectual ability based solely on the results of this study.
Even though the scientists governed for differences in the educational levels of the participants, they did not rule out the possibility that there were other factors that led to cognitive impairment. A response published in 2013 to a study that had been conducted in New Zealand implies that personal characteristics may be a factor in cannabis use as well as intellectual decline. The author used conscientiousness as an illustration in their work. Both narcotic use and poor performance on cognitive tests may be explained by a lack of conscientiousness on the part of the individual. According to the findings of a twin study that was conducted longitudinally in 2016, biological variants may also influence cognitive decline.
In this study, the researchers examined the changes in IQ that occurred in identical twins who used cannabis to those that occurred in their siblings who did not use marijuana. They did not discover any statistically significant differences in the rate of IQ decline between the two groups. The most important thing to remember? To gain a better understanding of the long-term consequences of marijuana use on intelligence, additional research is required.
Does It Make a Difference How Old You Are?
Individuals under the age of 25, whose brains are still developing, appear to be at greater risk from the negative effects of cannabis use.
Teenagers
Numerous unfavorable outcomes, according to the findings of research studies conducted on adolescents who used cannabis. Specifically, a review published in 2015 concluded that the use of marijuana by adolescents is affiliated with possibly permanent attention and memory deficiencies, brain structure changes, and unusual neural functioning. Furthermore, a study that was conducted over the course of 18 months in 2017 and referred to as a longitudinal studyReliable Source found that heavy use of cannabis was linked to declines in IQ and cognitive functioning.
Cannabis use in adolescents is associated not only with the development of mental health and substance disorders but also with supplemental cognitive deficits that can be triggered by these changes. Early marijuana use has been linked to an increased risk of a wide range of psychological conditions, including major depressive disorder and schizophrenia, according to a review that was conducted in 2013 by a Reliable Source. According to a report published in 2017, there is some evidence to suggest that beginning to use marijuana when one is still a teenager increases the likelihood of developing a cannabis use disorder in the future.
Adults
The impact that cannabis use has on the framework and activity of the brain in adults is not well understood. According to the findings of a review conducted in 2013, chronic marijuana use has the potential to alter both the structure and function of the brain in both adults and adolescents. A second review, which was also released in 2013, found that, on average, people who used cannabis had a smaller hippocampus than those who did not use the drug across the 14 studies that were included.
The findings led the scientists to the conclusion that consistent, long-term use of marijuana may be linked to the death of cells in the hippocampus. The hippocampus is an area of the brain that is affiliated with memory. According to the findings of another study from 2016, heavy pot smokers typically have lower scores in tests of neuropsychological function than people who do not use the drug. According to the findings of other studies, such as the one that was conducted in 2015, there are no discernible discrepancies between the brain volume and shape of people who regularly use marijuana and those who do not.
A longitudinal study that lasted for 25 years and was published in 2016 at a Reliable Source examined the relationship between cannabis use and cognitive ability in 3,385 attendees. On tests measuring memory recall and processing speed, the authors discovered that people who currently used marijuana had a poorer performance. However, it did not appear that cumulative exposure affected either the speed of processing or the executive function.
Conclusions That Can Be Drawn
- We are unable to conclude that the use of cannabis in any form typically causes any of the aforementioned changes in the brain’s structure or function.
- It’s possible that these are pre-existing differences that cause certain people to have a higher propensity to use cannabis in the first place, rather than effects that are a direct result of actually using marijuana.
- On the other hand, using drugs for the first time at a younger age, using them frequently, and using high doses are all associated with worse cognitive outcomes.
- There have only been a few studies that have looked into the differences in how smoking, vaping or consuming marijuana affects one’s cognitive abilities.
