Disadvantages of Legalizing Marijuana

Table of Contents

Marijuana is a psychoactive plant that can be used for multiple purposes, including the effect produced by smoking and ingesting it. The psychoactive plant has gained widespread popularity in America. Marijuana is now legalized for medical use in more than 37 states and recreational use in 18. However, marijuana is still illegal to use or distribute under federal law1.

According to the US government, marijuana is a mind-altering drug and classified as a Schedule I substance. Schedule I substances have a high potential for abuse, no accepted medical use, and a lack of accepted safety for use under medical supervision in the U.S.2.

Full Federal Legalization

There are many different avenues that policymakers, marijuana growers, enthusiasts, and the general public have supported to address marijuana’s growing presence in America. These include medical legalization, decriminalization, state legalization, and full federal legalization.

Full federal legalization would likely include a minimum age to smoke, a maximum amount to carry or purchase, limitations on consumption, and rules for driving under the influence. A purported advantage to legalization would be that the government could generate considerable wealth through taxes. It’s unclear if the taxes would be greater than the cost of regulation, FDA oversight, enforcement, and the potential health risk to the public.

Studies have shown that full federal legalization may lead to more cannabis use and perhaps addiction3. Marijuana use, both medical and recreational, has become more widespread and acceptable in public opinion. Even with this change in opinion, it is important to note several major disadvantages to fully legalizing marijuana.

Medical Use of Marijuana

Some states within the United States have allowed the use of marijuana for medicinal purposes. The U.S. Food and Drug Administration has the federal authority to approve drugs for medicinal use in the US. The FDA has not approved a marketing application for any marijuana product for any clinical indication. The FDA and DEA have concluded that marijuana has no federally approved medical use for treatment in the U.S2.

California’s Prop 215 legalized marijuana in the state and prompted the Institute of Medicine to release a report that examined cannabis’ potential therapeutic uses10. The report found the potential therapeutic value of cannabinoid drugs for pain relief, control of nausea and vomiting, and appetite stimulation. Smoked marijuana, however, is a crude THC delivery system that delivers harmful substances.

The psychological effects of cannabinoids, such as anxiety reduction, sedation, and euphoria, can influence their potential therapeutic value. Those effects are potentially unpleasant for some patients and beneficial for others. In addition, psychological effects can complicate the interpretation of other aspects of the drug’s effect.

Studies have found that marijuana can effectively relieve select symptoms of HIV/AIDS, cancer, glaucoma, and multiple sclerosis. There are some medical uses for marijuana, but it is argued that these benefits do not warrant the full legalization of marijuana under federal law.

Marijuana Side Effects

Marijuana is often purported to be a harmless drug, something to take the edge off, or even medicine. However, it is not without side effects and can be easily abused.

Side Effects Associated with Marijuana

Lack of Therapeutic Benefit

In the United States, commercially available drugs are subject to rigorous clinical trials to evaluate safety and efficacy. Data appraising the effectiveness of marijuana in conditions such as HIV/AIDS, epilepsy, and chemotherapy-associated vomiting is limited.

There has been only one randomized, double-blind, placebo-controlled study evaluating the efficacy of smoked marijuana for any of its potential benefits11. The study showed that marijuana treated nausea more effectively than placebo but less effectively than Ondansetron.

A review conducted recently found insufficient evidence to support the usage of smoked marijuana for several potential ailments. The review included chronic pain caused by rheumatoid arthritis, dementia, and ataxia. It also included tremors associated with multiple sclerosis, cachexia and symptoms of HIV/AIDS.

This does not mean that components of marijuana do not have potential therapeutic effects to alleviate onerous symptoms of these diseases. However, given the side effect profile of marijuana, the evidence to justify its use in these conditions is still lacking.

Widespread Off-Label Use

Cannabis is not subject to central regulatory oversight, unlike any other prescription drug used for medical purposes. Marijuana is grown in dispensaries or on farms. Depending on the state, the growing standards can vary from strict to almost non-existent.

The crude marijuana plant and its products may be infected with fungus or mold. This is especially problematic for immunocompromised patients. Full legalization, as it stands, is not set up to avoid this problem.

Another disadvantage to legalizing marijuana is that it enhances opportunities for the sellers on the black market. Prices charged by sellers licensed by the state and their taxes can easily be undercut by cartels. These sources of marijuana are often untrustworthy as the sourcing, methods of growing, and marijuana trafficking are often completed with dangerous methods4.

These problems are especially worsened in concentrated marijuana products like edibles and oils. Candy bars are traditionally one serving size, but a candy bar containing marijuana could contain up to four times the recommended dose of THC. Anxiety attacks or psychotic symptoms from eating sweets infused with marijuana can lead to ER visits.

Myth: Marijuana is Not Addictive

A common misconception among public opinion is that marijuana is not an addictive substance. The statistics demonstrate that about 10% of cannabis users become addicted; the rate is higher among adolescents2. Users who seek treatment for marijuana addiction average ten years of daily use.

As many as 47% of frequent users of marijuana experience withdrawal symptoms13. The drug may not have the same addictive potential as other narcotics like opiates. However, the belief that cannabis does not have a high potential for addiction is misguided.

Cannabis withdrawal syndrome (CWS) is a criterion of cannabis use disorder according to the Diagnostic and Statistical Manual of Mental Disorders- Fifth Edition (DSM-V)12. CWS is diagnosed if three or more symptoms are developed within one week of stopping cannabis use. The severity of withdrawal symptoms can vary based on the amount of use, personality traits, mental health disorders present, and life experiences.

Cannabis Withdrawal Syndrome

Marijuana & the Brain

Using marijuana before 18 years old may affect how the brain builds connections for functions like attention, memory, and learning. Marijuana’s effects on attention, memory, and learning may last a long time or even be permanent. Youth who use marijuana may not do as well in school and may have trouble remembering things5.

Psychotic Disorders

Psychotic disorders, such as schizophrenia, are consistently linked to marijuana use. An association between marijuana and schizophrenia meets most but not all of the standards for causation through experimental evidence9.

Genetic variation may explain why marijuana use does not always cause psychotic disorders. Marijuana use may be shown to cause or precipitate schizophrenia in a genetically vulnerable population. The risk of psychotic disorder is more pronounced when marijuana is used earlier.

Effects on Cognition

Regular cannabis use is related to changes in the brain’s natural reward pathways. Pre-existing conditions like genetics and early life experiences can increase the risk of developing cannabis dependence6.

The available evidence suggests that chronic cannabis use often does not produce severe impairment of cognitive functioning. Instead, the effects appear to be more subtle and no longer measurable after a few days to weeks of abstinence.

Starting regular cannabis use in early adolescence and continuing through young adulthood can lead to more pronounced, long-term cognitive deficits. There is an ongoing debate about whether heavy cannabis use results in permanent changes in cognition or whether cognitive deficits are reversible after extended abstinence from the substance.


Decision-making is a complex process that involves several cognitive abilities operating simultaneously. A recent study looked at aspects of decision-making among people who use cannabis frequently.

Although the available data is limited, heavy cannabis use and cannabis use disorder can be associated with poor decision-making 6. Altered brain activity in the regions regulating decision-making can also be affected by heavy cannabis use. It has been found that not all aspects of decision-making are affected equally. It is unclear whether heavy cannabis use leads to bad decisions or poor decisions lead to heavy cannabis use.

The Cost of Legalizing Marijuana

A fatal motor vehicle collision greatly increases when a driver is under the influence of marijuana. In Colorado, the number of DUIs increased the year following the legalization of Marijuana7. The number of fatal accidents behind the wheel associated with the use of marijuana also increased tremendously.

There may be some theoretical social benefits from legalizing recreational use in the context of domestic criminal justice policy. However, these benefits will not come without significant public health and social costs. The healthcare costs per year with marijuana are estimated to be $2,200 for heavy users, $1,250 for moderate users, and $650 for light users8.

Get Help Now

With public opinion regarding marijuana being so popular, it can be easy to think that it must be okay to partake. It is important to remember that everyone reacts differently to this drug, and adverse effects can happen despite prior positive reactions.

If you or someone you love are struggling with marijuana use or abuse, please reach out to  Inland Detox. Our team can answer any questions you may have or give you a better understanding of our inpatient program.

  1. National Conference of State Legislatures (2022, February 3). State Medical Cannabis Laws. Retrieved March 9th, from https://www.ncsl.org/research/health/state-medical-marijuana-laws.aspx
  2. Department of Justice (2020 April). Drug Fact Sheet. Retrieved March 9th, from https://www.dea.gov/sites/default/files/2020-06/Marijuana-Cannabis-2020_0.pdf
  3. Cerda, M Dr.PH (2019, November 3). Association Between Recreational Marijuana Legalization in the United States and Changes in Marijuana Use and Cannabis Use Disorder From 2008 to 2016. Retrieved March 9th, from https://jamanetwork.com/journals/jamapsychiatry/article-abstract/2755276
  4. Britannica (2018, November 13). Should Recreational Marijuana Be Legal? Retrieved March 9th, from https://marijuana.procon.org/
  5. Center for Disease Control and Prevention (2020, October 19). Brain Health. Retrieved March 9th, from https://www.cdc.gov/marijuana/health-effects/brain-health.html
  6. Canadian Centre on Substance Use and Addiction (2019). Clearing the Smoke on Cannabis. Retrieved March 9th, from https://www.ccsa.ca/sites/default/files/2019-04/CCSA-Cannabis-Use-Cognitive-Effects-Report-2019-en.pdf
  7. CDPS. (2021, July 19). Colorado Division of Criminal Justice publishes report on impacts of marijuana legalization in Colorado. Colorado Division of Criminal Justice Publishes Report on Impacts of Marijuana Legalization in Colorado | Division of Criminal Justice. Retrieved April 8, 2022, from https://dcj.colorado.gov/news-article/colorado-division-of-criminal-justice-publishes-report-on-impacts-of-marijuana
  8. Hunt, J. (2019, March 25). Economic and social costs of legalized marijuana. Centennial Institute. Retrieved April 8, 2022, from https://centennial.ccu.edu/policy-briefs/marijuana-costs/
  9. Patel, S., Khan, S., M, S., & Hamid, P. (2020, July 21). The association between Cannabis use and schizophrenia: Causative or curative? A systematic review. Cureus. Retrieved April 8, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7442038/
  10. US Department of Justice. (1999). Marijuana and medicine: Assessing the science base, executive summary. Marijuana and Medicine: Assessing the Science Base, Executive Summary | Office of Justice Programs. Retrieved April 8, 2022, from https://www.ojp.gov/ncjrs/virtual-library/abstracts/marijuana-and-medicine-assessing-science-base-executive-summary
  11. Söderpalm , A. H., de Wit, H., & Schuster, A. (2001). Antiemetic efficacy of smoked marijuana: Subjective and behavioral effects on nausea induced by syrup of ipecac. Pharmacology, biochemistry, and behavior. Retrieved April 8, 2022, from https://pubmed.ncbi.nlm.nih.gov/11509190/
  12. Bonnet, U., & Preuss, U. W. (2017, April 27). The cannabis withdrawal syndrome: Current insights. Substance abuse and rehabilitation. Retrieved April 8, 2022, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5414724/
  13. Bahji, A., Stephenson, C., Tyo, R., Hawken, E. R., & Seitz, D. P. (2020, April 9). Cannabis withdrawal symptoms in people with regular or dependent cannabinoid use. JAMA Network Open. Retrieved April 12, 2022, from https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2764234