Long-Term Effects of Cannabis on Brain Structure - Essay Example

Brain behaviour relationships: Effect of Cannabis use on Brain behaviours and development Name Institution Introduction The 2011 Monitoring the Future Study, as Jacobus and Susan Tapert (2014) show, provided evidence that cannabis is by far the most consumed illegal drug by adolescents in the United States. Indeed, cannabis has been recognised as the most regularly consumed illegal substance during the last four decades. The increase in use of the substance, specifically among adolescents and young adults, has drawn greater attention on its potential detriments and advantages (Lubman et al., 2014). Current studies indicate that 23 percent of twelfth graders in the United States confess to have used cannabis within the last one month (Jacobus & Tapert, 2014). There are also concerns that the use of cannabis by the adolescents may have serious effects on their academic functioning, and social functioning, which could extend into their later lives (Jacobus & Tapert, 2014; Filbey et al., 2014). On the other hand, since maturational or developmental brain changes still occur in the brains of the adolescents and into adulthood, there is a concern among scholars that use of cannabis during this stage may have significant effect on their brain development (Squeglia et al., 2009; Zalesky et al., 2012). Based on this background, it becomes clear that there is a need to establish the effects of cannabis on brain behaviours and brain structures, as well as whether the effects are linked to age of onset of regular cannabis use. This essay argues that long-term use of cannabis impairs the white matter of the brain that still develops. Additionally, when the age of onset of regular use of cannabis is delayed, the intensity of micro-structural impairment may be minimised. Regular use of cannabis causes changes in the brain structure of users, although the severity of the effects depends on age of onset of regular use. Battistella et al. (2014) examined whether regular use of cannabis is linked to the differential effects on brain structure, depending on the users’ age. They were primarily concerned with whether the use of cannabis by adolescents affects the user’s brain structures at their later ages during adulthood. Battistella et al. (2014) investigated the specific nature of structural changes that cannabis induces. The changes in brain structure were studied within a group of people who regularly used cannabis. The data was then compared with a group of people who used cannabis occasionally. The findings provided proof that regular smoking of cannabis is linked to the reduction in the grey matter volume in the orbitofrontal cortex, temporal pole, medial temporal cortex, insula, and parahippocampal gyrus. Therefore, cannabis causes changes in the brain structure of users, although the severity of the effects depends on age of onset of regular use. Consistent with the above findings, Battistella et al. (2014) also observed that the age of onset of cannabis use influences the degree of the changes in the brain structure. They concluded that a decline in substantial amounts of grey matter volume might come about from heavy use of cannabis that is, however, not related to the age of onset of use of cannabis (Battistella et al., 2014). On the other hand, the significant grey matter volume found in the cerebellum of individuals who regularly smoked cannabis without any link to the monthly use of cannabis is linked to developmental processes that happen during adolescence and stop during adulthood (Battistella et al., 2014). According to the California Society of Addiction Medicine (2009), this is because the brain still undergoes significant development until one reaches the age of 25 years. Cannabis use leads to alteration of brain structures, hence impairing their functions. According to Zalesky et al. (2012), cannabis use, in general, starts during adolescence or during the early adulthood. During the period, cannabinoid receptors are still concentrated in the white matter pathways in the brain. It is based on this backdrop that Zalesky et al. (2012) were prompted to investigate the impact of regularly smoking cannabis on white matter structure. They further investigated the axonal fibre pathways in the brain to determine any micro-structural changes to the brain as caused by the long-term smoking of cannabis, as well as to test if age of onset of regular use of cannabis is linked to the seriousness of the micro-structural alterations. Their findings confirmed that axonal connectivity becomes impaired from regular use of cannabis, within the right fimbria of the hippocampus. At the same time, it was established that axial and radial diffusivity within the right fimbria of the hippocampus were linked to age of onset of regular use of cannabis. In a related study, Battistella et al. (2014) observed that during adolescence, proper structural maturation of the fibre tracts in the brain happen, which are essential for sensory, motor, and cognitive functions. For this reason, the use of cannabis can change the maturational arrangements, which affect the adolescents’ brain. Past studies established that such factors potentially increase the likelihood of mental disorders (Paus et al., 2008). In Zalesky’s et al. (2012) study, it was also established that a linear correlation exists between the age of starting to regularly use cannabis and elements of the white matter (WM) integrity. This shows the toxic consequence of using cannabis for long periods and the development of the white matter. In a study by Filbey et al. (2014), the researchers sought to explain the changes in brain structures as a result of chronic use of cannabis. They then measured grey matter (GM) volume through structural MRI in the entire brain through the use of voxel-based morphology. Their findings indicated that when it comes to control, the chronic users of cannabis have substantially minimal bilateral orbitofrontal gyri volume yet high functional connectivity in the orbitofrontal cortex (OFC) network. The greater OFC functional connectivity among smokers of cannabis was linked to earlier age of onset. The effects of cannabis use on the brain tend to be minimal during adolescence yet more intense during adulthood. In their study, Jacobus and Tapert (2014) observed that Cannabinoid receptors (CB1) are distributed broadly in the brain and trigger neurotransmitter release and their quantity in the neural systems. In his view, the concentration of the CBI tends to increase adolescence, and as a result cause genetic expression of neural growth. On the other hand, change of the endocannabinoid system may happen due to regular use of cannabis during adolescence, leading to a cascading neurostructural and neurochemical aberrations, hence contributing to emotional outcomes and poorer cognitive during adulthood. Jacobus and Tapert (2014) were of the view that the effects are minimal during adolescence yet more intense in adulthood. Disruptions in brain development as a result of regular use of cannabis tend to change neuro-developmental trajectories. A study by Jacobus and Tapert (2014) established that disruptions in brain development as a result of neurotoxic effects brought about by regular use of cannabis may substantially change neuro-developmental trajectories altering neurochemical communication, as well as the genetic expression associated with brain development, yet contribute to detrimental effects on the brain tissue. These cannabis-related consequences on grey matter and white matter structures may have significant effects on the healthy development of brain from childhood into adolescents and adulthood on the brains cognitive functioning. Acute use of cannabis has significant effects on motor and cognitive functions. As stated by Crean et al. (2011) smoking cannabis has damaging effects on the cognitive functions in different levels, such as basic motor coordination, and controlling emotions. Such deficits range in the degree of severity condition on the amount, age of onset, and duration of consumption. Crean’s et al. (2011) study established that people with cannabis-associated harm in executive functions tend to have difficulty in learning. They further established that the trajectory of the impacts of cannabis on executive functions pursues a remarkable pattern of recovery of certain functions, such as information processing abilities of the brain. Additionally, acute consumption of cannabis was found to impair inhibition and to encourage impulsivity. Chronic and heavy consumption of cannabis was also found to affect the individual users’ verbal fluency capacity after abstaining for a long time. Still, occasional consumption of cannabis was also found to acutely impair users’ concentration, inhibition, attention, decision-making, working memory and impulsivity (Crean et al., 2011). A related study by Jacobus and Tapert (2014) of adults who regularly use cannabis found slight reductions in the performance of the users in comparison to the controls in cognitive facets like memory, attention, and information processing speed. Jacobus and Tapert (2014) also established that cannabis also had effects of the cognitive development on adolescents, in the areas of memory and executive functioning, and principally in the specialized functions, such as cognitive control, which were also found not to have strongly links to neocortical and adolescence tissue maturation, yet may have significant effects on their perception of risk and school performance. Conclusion From the above review, it becomes clear that long-term use of cannabis impairs the white matter of the brain that still develops. It is also clear that when the age of onset of regular use of cannabis is delayed, the intensity of micro-structural impairment may be minimised. Acute cannabis use leads to alteration of brain structures, hence impairing the functions of these structures. These affect the motor and cognitive functions of the brains of the users, leading to impairing of basic motor coordination and controlling of emotions. Such deficits range in the degree of severity conditional on the amount of cannabis intake, age of onset of chronic use, and duration of consumption. Therefore, regular use of cannabis causes changes in the brain structure of users, although the severity of the effects depends on age of onset of regular use. References Battistella G, Fomari E, Annoni J, Dao K, Favrat B, Mall J, Maeder P & Giroud. (2014). Long- Term Effects of Cannabis on Brain Structure. Neuropsychopharmacology. 39(9): pg. 2041–2048. California Society of Addiction Medicine (CSAM). (2009). Impact 'of' Marijuana on Children and Adolescents. San Francisco: CSAM. Crean R, Crane N & Mason. (2011). 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Effect of long-term cannabis use on axonal fibre connectivity. Brain: A Journal of Neurology, 135(7), 2245-55 Read More