Over the past decade, more and more studies have arisen arguing the positive and negative health effects of marijuana. Partially due to its recent legality, scientists have decided to study whether or not marijuana is actually less harmful of a substance than tobacco and alcohol.

The degree of harm in which marijuana can have on your body is dependent on the drug’s potency (the strain), the frequency of use and the age of the user (Boffey 1). The age matters because brains do not fully develop in an adolescent until the early 20’s. However, it is found that adults who smoke casually and infrequently pose little to no health risks (Boffey 2).

An independent scientific committee in Britain compared 20 drugs and their effects onto individuals in regards to crime, illness and family life. Alcohol ranked first while marijuana ranked eighth, “having slightly more than one-fourth the harm of alcohol” (Association Between Marijuana Exposure and Pulmonary Function Over 20 Years). Many opponents of marijuana legalization claim that if it were legal, then the detrimental effects would equal that of alcohol and tobacco. However, a 1995 study for the World Health Organization concluded that, “even if usage of marijuana increased to the levels of alcohol and tobacco, it would be unlikely to produce public health effects approaching those of alcohol and tobacco in Western societies” (Boffey 7). In addition to this, there is no clear causal connection between marijuana and a deadly disease, such as cancer and cirrhosis, both which alcohol can. Very heavy marijuana smokers can experience symptoms of bronchitis, such as wheezing and coughing. A 2012 study in the United Kingdom found that, “smoking a joint a day for seven years was not associated with adverse effects on pulmonary function” (Drug Harms in the UK: A Multicriteria Decision Analysis). Despite this, skeptics and opponents of marijuana use claim that it is addictive, like alcohol and tobacco, which is why it should remain an illicit Schedule I drug, a drug that has a high potential for abuse. So, scientists tested this claim.

There is a seed of truth to this claim, but it is very minute. In a 1999 study, the non-partisan Institute of Medicine, an NGO founded by congressional charter in 1970, found that only 9 percent of marijuana users develop dependence, compared to 32 percent of tobacco users and 15 percent of alcohol consumers. This study also states that, though it is rarely the case, it is possible to develop dependence to the drug. That being said, the dependence is far less severe than that of other more harmful drugs (Boffey 6).

The greatest cause for concern is the physical impact of marijuana smoking on young adolescents/adults who have not yet fully developed their brain, specifically their pre-frontal cortex which can affect memory, motivation and executive functions such as planning. There is little evidence that frequent use among young people affect I.Q. points. A study in New Zealand in 2012 found that “people who began smoking heavily in their teens and continued into adulthood lost an average of eight I.Q. points by age 38” (Boffey 3). However, a Norwegian researcher challenged this case who stated that socio-economic factors may have played a role in the I.Q. loss. All this being said, the National Institute on Drug Abuse settled this debate by concluding that “adults who smoked heavily in adolescence had impaired neural connections that interfered with the functioning of their brains…but it is unclear whether consumption triggered the poor grades” (Boffey 4). Critics also condemn marijuana as a “stepping stone” to harder drugs. However, scientists at the Institute of Medicine disprove this criticism, stating, “marijuana does not appear to be a gateway drug to the extent that is the cause or even that it is the most significant predictor of serious drug abuse…the real gateway drugs are tobacco and alcohol, which young people turn to first before trying marijuana” (Boffey 5).

There will continue to be challenges for regulators in the nation to legalize marijuana. The hope is that more scientists are willing to publicize positive findings about the positive, and negative, effects of marijuana in the face of historic contempt towards the drug. In doing so, society may be rid of some of the negative, untrue and outdated stereotypes attached to marijuana that were founded years ago by lack of scientific resources.




Boffey, Philip M. “What Science Says About Marijuana.” The New York Times. The New York Times, 30 July 2014. Web. 17 Nov. 2014.

Nutt, David J., Leslie A. King, and Lawrence D. Phillips. “Drug Harms in the UK: A Multicriteria Decision Analysis.” The Lancet 376.9752 (2010): 1558-565. 1 Nov. 2010. Web. 17 Nov. 2014.

Pletcher, Mark J. “Association Between Marijuana Exposure and Pulmonary Function Over 20 Years.” JAMA. American Medical Association, 11 Jan. 2012. Web. 17 Nov. 2014.



Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.