The Health Effects of Marijuana Use

Despite more than 70 years of well-reasoned restriction of marijuana use in the United States and persistent problems of abuse, there are increasing efforts to achieve legalization of marijuana. Medical use of marijuana has prompted many states to establish programs for the sale of prescription marijuana.  Some states have legalized recreational use of marijuana supported by voter-approved referenda.  Still others have suggested “decriminalization” of marijuana even though this shift in terminology offers little change in the end result of encouraging free and ready access to marijuana for recreational purposes. Supporters of legalization have become increasingly bold in openly campaigning for public acceptance. However, even limited legalization in some states has led to significant increases in usage. Research reveals the grave risks associated with chronic use of marijuana in adolescents. In advocating for the “Best for Children,” the American College of Pediatricians (ACPeds) supports legislation that would continue the prohibition of the sale and recreational use of marijuana.

Visit this link to see a full statement from the ACPeds, Marijuana Use: Detrimental to Youth.

Visit this link to to see a full statement from the ACPeds, Effect of Marijuana Legalization on Risky Behavior in Adolescents.

More Information on Marijuana Use:

Are Marijuana Use and Suicide Linked? — A review of the data show there's cause for alarm April 2021

Association of cannabis use in adolescence and risk of depression, anxiety and suicidality in young adulthood: A systematic review and meta-analysisJAMA Psychiatry, 2019 DOI: 10.1001/jamapsychiatry.2018.4500

Existing research suggests that initiation of cannabis use in adolescence is associated with long-term neurocognitive effects. Gray matter volume differences associated with extremely low levels of cannabis use in adolescents. Journal of Neuroscience, January 2019.

Cannabis tied to more adverse cognitive outcomes than alcohol in teens.  Adolescents who used cannabis had lower scores in cognitive tests measuring working and short-term memory, perceptual reasoning and inhibition, compared with those who drank alcohol, Canadian researchers reported in the American Journal of Psychiatry. The findings were based on data involving 3,800 Canadian 13-year-olds who were followed for four years.

Marijuana Mental Illness and Violence. February 2019: 

Early marijuana use associated with abnormal brain function, study revealsOctober 2016. In a new study, scientists in London, Ontario have discovered that early marijuana use may result in abnormal brain function and lower IQ. Previous studies have suggested that frequent marijuana users, especially those who begin at a young age, are at a higher risk for cognitive dysfunction and psychiatric illness, including depression, bipolar disorder and schizophrenia. Dr. Elizabeth Osuch, a Scientist at Lawson Health Research Institute and the Dr. Joseph Rea Chair in Mood Disorders at the Schulich School of Medicine & Dentistry at Western University, is a Canadian leader in studying both mood and anxiety disorders and the effects of marijuana.

The Effects of Cannabis on Embryonic Development.  September 2016. The effects of cannabinoids on pre-implantation and embryologic development have the potential to elicit harmful outcomes post-natally. While the method of consumption can affect the severity of the embryologic effects, it is important to note that this paper is an overview of the effects solely of elevated cannabinoid signaling. A common means of cannabis consumption is smoking, which can add a number of toxins and thereby amplify harmful effects to the embryo. Given the trend of marijuana decriminalization and legalization across the United States, further epidemiological research should focus on the association between maternal cannabinoid use and observation post-natal outcome.

The Legalization of Marijuana in Colorado: The Impact is a compilation of data by the Rocky Mountain High Intensity Drug Trafficking Area that analyzes the effects of marijuana legalization in the state. This third volume allows readers to compare and contrast statistics observed from 2006 – 2009 during Colorado’s early medical marijuana era with those from 2009 to 2013 as medical marijuana commercialization grew, and also with those from the current legalized recreational marijuana era from 2013 to the present. The statistics reveal that between 2013 and 2014 there was a 45% increase in marijuana-associated impaired driving, a 32% increase in marijuana-related motor vehicle deaths (with a 92% increase from 2010 to 2014), as well as 29% and 38% increases in emergency room visits and hospital admissions secondary to marijuana use. By 2013, marijuana use in Colorado was 55% above the national average among teens and young adults, and 86% higher among those over age 25. Diversion of marijuana from Colorado to other states has also increased several fold. This new data further supports the College Position Statement above emphasizing concerns that marijuana legalization will result in increased adolescent usage, addiction and its associated risks for them.

A win for big marijuana is a major loss for children – as published November 13, 2014 at

Problems with the Medicalization of Marijuana as published June 18, 2014 in the Journal of the American Medical Association.

Teenagers’ rapidly developing brains put them at high risk of harm from marijuana use, a review of the drug’s adverse effects emphasizes. See this article, Marijuana use and adolescence don’t mix, published at Contemporary Pediatrics on June 14, 2014.

According the the American Academy of Child & Adolescent Psychiatry  in an April 2014 Policy Statement Legalization of marijuana for medicinal or recreational purposes, even if restricted to adults, is likely to be associated with (a) decreased adolescent perceptions of marijuana’s harmful effects, (b) increased marijuana use among parents and caretakers, and (c) increased adolescent access to marijuana, all of which reliably predict increased rates of adolescent marijuana use and associated problems. Marijuana use during pregnancy raises additional concerns regarding child and adolescent development.

In the news April 2014 – Casual pot use causes brain abnormalities in the young: study
Study author Dr. Hans Beiter commented on the study published by the Journal of Neuroscience. The study revealed structural changes in the brain regions involved in regulating emotion and motivation, of young people who smoke one to seven joints each week. The abnormalities “may be an early sign of what later becomes amotivation, where people aren’t focused on their goals.”

Cannabis and the Adolescent Brain by Robert J. Hilton, MD

Changes in Cannabis Use in Young People August 2013.

In the NY Times June 2014 – Politicians prescriptions for marijuana defy doctors and data

Partnership for Drug-free Kids- Parents: How to Talk with Kids about Vaping

Op Ed in LA Times June 2014 – We need to start child-proofing pot

California Cannabis Health Information Initiative – Youth and Cannabis

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