Running head: MARIJUANA: THERAPY & CONSEQUENCE
Marijuana: A Brief Overview of Therapeutic Purposing, Neurobiological Alteration &
Deleterious Consequences
Justin M. Lampert
Florida School of Professional Psychology
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A vast amount of research has been conducted over the past near-century regarding the
effects of heavy marijuana use on cognitive function, brain development, risk-taking behavior,
and a positive correlation with prediction of use regarding other, more dangerous substances.
A meta-search was conducted through Google Scholar, revealing over 13,000 separate
peer-reviewed entries containing the search termsmarijuanaandcognit*orbrainwithin the
title. The earliest article dating back to 1936 (Dewry) and multiple recent works (within the
past 3 months) specifically addressing the impact of THC abuse and cognitive functioning
and/or brain structure (Douet et al, 2017; Gruber & Sagar, 2017; Mandelbaum & de la Monte,
2017; Thames et al, 2017). Articles addressing the impact of marijuana on general function
are overwhelming in quantity. Arguably, regarding cognitive impairment, evidence has
shown that impairment occurs, most dramatically, within the realms of attention and working
memory (Pope & Yurgelun-Todd, 1996; Volkow et al., 2014). With the recent push for
legalization in terms of therapeutic and recreational use, research will undoubtedly match the
pace of ever-changing policy. In fact, likely a result of recent legislation and policy change, a
growing body of research has begun to highlight the potential for cannabis to make a positive
impact both within and outside of a medicinal context.
While the consequences of short-term use are often thought of as mirroring long-term
use in terms of similar effects to a lesser degree, more recent research indicates that extended
and/or heavy-use of marijuana has more complex outcomes (Volknow et al., 2014;
Mandelbaum & de la Monte, 2017). Additional emphasis is placed on the developmental
stage when marijuana use or abuse begins, with exceptionally detrimental effects occurring
during adolescence. Heavy use is often associated with an impairment in immediate memory
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and information retention, judgment or decision-making abilities, an alteration in the
structural development of the brain and an increase the potential to develop (or trigger) other
neurologically-based psychiatric disorders, such as schizophrenia (Volknow et al., 2014).
The main chemical components of marijuana, in general terms, are cannabinoids.
However, contrary to common belief, cannabinoids do not consist solely of
tetrahydrocannabinol (THC), typically associated with the euphoric effect desired from
recreational use. Cannabidiol (CBD), a second cannabinoid focused on in research, has less
euphoric effects and limited implications regarding cognitive functioning (Mandelbaum & de
la Monte, 2017). THC is responsible for psychoactive effects and is simultaneously
accredited for inducing states of heightened anxiety (Fusar-Poli et al., 2009) and anecdotal
purposing as an anxiety or fear-reducer. Conceptualizations are further exhibited through
paradoxical applications, such as links between cancerous cell-modification caused by
marijuana followed by use in the treatment of nausea resulting from subsequent
chemotherapy.
Literature appears to take a “chicken vs. the egg” approach to how cannabis and
severe mental illness interact. In other words, does marijuana use serve as an etiological basis
for disorders or simply exacerbate or trigger preexisting conditions? Some research, such as
Di Forti, et al., (2014), suggests that there is a positive correlation between heavy marijuana
use and age of onset. Their findings may suggest a “triggering effect” whereupon the active
psychosis could be perceived as lying dormant and was activated earlier than what “would
have been” if it were not for regular substance use. Schneider & Koch (2003) found
comparable results in that marijuana use correlates with early onset severe mental illness;
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however, they suggest this outcome as being a modification of brain structure during this
highly-important developmental stage. In a particularly thorough longitudinal study
conducted by Caspi et al. (2005) determined that gene modification occurs through regular
use, but did not impact each participant equally.
Within the context of risk-taking behaviors, a positive correlation exists between
frequent marijuana use and other potentially dangerous actions and hazardous behaviors
because of intoxication (Volkow et al., 2004). Further, evidence suggests that marijuana is
approached more casually by a wide range of age groups and that our culture’s dismissive
view of potential consequences has diminished (UnitedStates Department of Health and
Human Services, 2016). Thus, we could infer thatuse has increased because of an altered
approach to the drug’s potential harm.
Marijuana has been perceived as an indicator or “red flag” for other potentially
self-destructive behaviors during adolescence with often opposing stigmatization between
youth and caretakers. One of the most common concerns is that marijuana can serve as an
introductory drug to other substance addictions. While research has undoubtedly varied in
results, often paralleling the public’s level of vehemence in the “war on drugs” that has
fluctuated over the past several decades, some research has produced more “neutral” or
balanced results. Per example, Morral, McCaffrey, & Paddock (2002) suggest that while a
“gateway effect” may exist, that confounded variables and dramatization can often overstate
the correlation between prediction of additional substance abuse and marijuana consumption.
A biological explanation is provided by Pistis et al. (2004), suggests that the “gateway effect”
may not necessarily be a product of learned behaviors, but rather an increased sensitivity to
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dopamine receptors. The decrease in reactivity leads to an increase in future potential for
other addictions, inclusive of any behavior that triggers the dopamine reward system.
Reports of therapeutic use remains somewhat unreliable in nature and are typically
story-driven, although research has begun to provide some empirical evidence for conditions
that may benefit from marijuana use. In terms of more reliable and by extension, empirical
research, focus tends to be placed on “medically pure” or synthetic cannabinoids extracted to
a THC or CBD-based liquid, in comparison to typical marijuana leaf consumption (Joy,
Watson, & Benson, 1999). It remains to be seen if marijuana will be considered the “go-to”
method or if a more traditional approach will remain preferred in the treatment of said
diseases. In fact, Mandelbaum & de la Monte (2017) states that there are “few objective data
supporting preferential use over conventional therapy…” While not intended as a
comprehensive list, as cited through Volkow et al. (2014), pain treatment, glaucoma, nausea
(primary and secondary symptom), eating disorders, multiple sclerosis and epilepsy have been
studied with positive findings regarding the efficacy of controlled marijuana use.
Often presented as a one-sided concept in popular media, especially within the context
of policy, active cannabidiols (THC & CBD) appear to simultaneously create and mitigate
pathology. Numerous factors, such as innate inclination for risk-taking, predisposition to
psychopathology, environmental influence appear to play a significant role in the detrimental
effects that arise from continual marijuana use, especially during important neurological
development stages such as adolescence. However, while potentially oversold in terms of the
quantity and efficacy of conditions positively affected, the active chemical components are
not without merit. Empirical evidence has demonstrated efficacious therapeutic use for
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physiological and psychological conditions, though time will tell if more traditional means of
treatment are employed with a higher regularity than marijuana.
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References
American Psychiatric Association. (2013). Diagnosticand statistical manual of mental
disorders ( 5th ed.). Washington, DC: American PsychiatricPublishing.
Dewry, P. (1936). Some psychiatric aspects of marijuana.Psychiatric Quarterly, 10(2), 232-
242.
Douet, V., Chang, L, Stoytcheva, B. & Ernst, T. (2017). Sex differences on cortical brain
morphometry and behaviors in adolescent marijuana use.Department of Medicine.
Honolulu, HI: University of Hawaii.
Fusar-Poli, P., Crippa, S. & Bhattacharyya, P. (2009). Distinct effects of {delta}9-
tetrahydrocannabinol and cannabidiol on neural activation during emotional
processing.Archives of General Psychiatry, 66, 99-104.
Gruber, S., & Sagar, K. (2017). Marijuana on the mind? The impact of marijuana on
cognition, brain structure, and brain function, and related public policy implications.
Behavioral and Brain Sciences, 4(1), 104-111.
Joy, J., Watson Jr., S., & Benson, J.Marijuana andmedicine: Assessing the science base.
Washington, DC: National Academy Press.
Mandelbaum, D., & de la Monte, S. (2017). Adverse structural and functional effects of
marijuana on the brain: Evidence reviewed.PediatricNeurology, 66, 12-20.
Morral, A., McCaffrey, D., & Paddock, S. (2002). Reassessing the marijuana gateway effect.
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Pistis, M., Perra, S., Pillolla, G., Melis, M., Muntoni, A., & Gessa, G. Adolescent exposure to
cannabinoids induces long-lasting changes in the response to drugs of abuse of rat
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Pope, H. & Yurgelun-Todd, D. (1996). The residual cognitive effects of heavy marijuana use
in college students.JAMA Internal Medicine, 257(7),521-527.
Schneider, M. & Koch, M. (2003). Chronic pubertal, but not adult chronic cannabinoid
treatment impairs sensorimotor gating, recognition memory and the performance in a
progressive ratio task in adult rats.Neuropsychopharmacology,28, 1760-1769.
Thames, A., Kuhn, T., Williamson, T., Jones, J., Mahmood, Z., & Hammond, A. (2017).
Marijuana effects on changes in brain structure and cognitive function among HIV+
and HIV- adults.Drug and Alcohol Dependence, 170,120-127.
United States Department of Health and Human Services. National Institute on Drug Abuse.
(2016). Retrieved from: https://www.drugabuse.gov/related-topics/trends-
statistics/infographics/monitoring-future-2016-survey-results
Volkow, N., Baler, R., Compton, W., & Weiss, S. (2014). Adverse health effects of marijuana
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