The human brain is always in an active state; in an experience-lead development, the brain follows our life from inside the womb, childhood, and adolescence, which science reveals happens until the age of about 21 years. During these stages of development, the brain is essentially more vulnerable than a mature brain, especially to the long-term negative effects of environmental attacks, such as exposure to the active components of the marijuana drug.
Studies find that adults who smoke regularly have actually impaired the neural connectivity (or fewer fibers) in particular brain regions. These regions include the precuneus, which is a key node involved in bodily functions requiring high degrees of integration, such as self-conscious awareness and alertness. Moreover, the area of the hippocampus called the fimbria is important in memory and learning. There also reports on reduced functional connectivity, specifically in the prefrontal networks – these are responsible for our body’s executive function, which pertains to inhibitory control. There’s also the subcortical networks, a process of which allows our brains to form routines and habits. In addition to this study, people who have used marijuana show a decreases activity in prefrontal regions, along with reduced brain wave volumes in the hippocampus. The evidence gathered then clearly shows that certain brain regions can be more vulnerable to the long term negative effects of marijuana.
Of course, as already mentioned, the negative effects of marijuana use on brain development and functional connectivity is much more prominent during marijuana use in young adulthood and adolescence. This correlation helps explain the association between frequent use of marijuana during this particular life period and significant decreases in the IQ. Such impairments in the brain functions and connectivity associated with marijuana exposure in young adulthood are consistent with clinical findings, which merely indicate that the presence of marijuana components in the human system, indeed, plays a prominent role in the formation and development of our brains.
More than affecting the technical brain functions, data further suggests that the use of marijuana in youth adulthood could enable the formation of multiple addictive behaviors, all manifesting in adulthood. In an experiment carried out on rodents, exposure to marijuana in the adolescent stage has shown that there is a decreased reactivity of the dopamine neurons, an area of which modulates our brain’s reward system region. Following this information, if the reduced dopamine reactivity in the brain’s reward system region happens due to early exposure to marijuana, then it could explain the individual’s increased susceptibility to drug abuse and addiction to other later in life. This particular occurrence is evident in other studies, particularly with other animal experiments showing that marijuana has the capacity to prime the brain for stronger responses to other drugs.
Although these findings sustain the theory that marijuana is a gateway drug, those other drugs, like nicotine and alcohol, can also be seen as gateway drugs. There is enough evidence to point out that alcohol and nicotine both have the components to prime the brain for other kinds of drug use. However, some experts offer an alternative explanation; people who susceptible to drug abuse are more likely to begin with marijuana, simply because of its accessibility and the social interactions with other drug users trailing right behind.
It’s only natural that we discuss the effects of marijuana on an individual’s school performance and lifetime achievements, as these are closely linked to brain development. In 2013, a survey was conducted by Monitoring the Future, featuring high school students and marijuana. It has found that a number of 6.5% students in 12th grade admit to daily or near-daily marijuana use; this figure, however, perhaps represents an underestimate of marijuana use, since the frequent marijuana users among the youth usually have a history of dropping out. As established, marijuana use leads to the impairment of critical cognitive functions, which occurs during the acute intoxication and even days after use. With this in mind, it can be said that students who frequent the use of marijuana could be operating at a brain cognitive level below their natural capabilities, which can happen for extensive time periods. Although the rather acute effects subside after the components of marijuana is cleared from the brain, continuous marijuana use still poses serious risks to overall health that accumulates after heavy and long-term use. Moreover, there is even the potential to fail in learning in school, even for sporadic periods of time. This naturally interferes with educational goals, which can then explain the findings on the association between frequent marijuana use and poor grades.
However, it is important to note that the relationship between marijuana use by young people and the harms they pose is most likely multifaceted, which explains the presence of inconsistencies in relevant studies. For instance, some studies propose that long-term brain discrepancies may be reversible, or be reduced into subtlety, rather than disabling once a person withdraws from marijuana use. More studies, on the other hand, depict impairments in memory and attention, which follows after long-term and heavy marijuana use. This persists and worsens year after year, with the initial use beginning during adolescence. As mentioned earlier, early marijuana use is often linked to poor school performance and dropout rates, but heavy marijuana use has also been associated with unemployment, lower income, criminal behavior, socioeconomic dependency, and lower life satisfaction.
Marijuana, next to alcohol, is the most explicitly used drug all over the world. If we look at alcohol alone, 25% of adolescents reveal their experiences of being drunk the past month, closely following their report of using marijuana, at 23%. In a recent commentary, Swanson and Gonzalez point out that rates of marijuana prevalence among high school students increase every year, going up from 22% to 36% in the last decade. The perceived risk of use, on the other hand, has dropped, as 80% of the high school students do not believe that regular marijuana use poses any health risk. The mentioned literature, however, specifies only neurocognitive disadvantages – this means only dangers that pertain to decrease in attention and memory, persisting beyond marijuana abstinence. There are also possible brain alterations, some of which that affects the actual brain – changes in gray matter tissue, white matter fibers, and neurovascular functions. Of course, earlier engagement with marijuana and heavy use is associated with even poorer health conditions.
From all that has been discussed, it is also essential to discuss that despite the abundance of evidence, it remains to be difficult to ascertain brain condition differences in groups. There are factors, of course, that lead to substance abuse and risky behaviors, and there are some factors that come at play instead. Nonetheless, it’s clear that there are differences in the integrity in brain matter following heavier use of marijuana.