The Dangerous Effects of Marijuana Legalization on Teenagers

Reading Time: 5 minutes

The effects of marijuana legalization on teenagers are crucial for parents in the United States to understand. At this point, 33 states and the District of Columbia (Washington DC) have legalized marijuana for medical use. Additionally, 10 of those states have legalized marijuana for recreational use as well.

Thus, as of March 2019, the states where marijuana is legal for recreational use by adults include:

  1. Alaska
  2. California
  3. Washington State
  4. Oregon
  5. Nevada
  6. Colorado
  7. Michigan
  8. Massachusetts
  9. Vermont
  10. Maine

Consequences of Legalizing Marijuana and Recreational Use

Teen health and teens’ perception of the drug are impacted by the effects of marijuana legalization for recreational use. Along with the political and economic discussions regarding this issue, the consequences of legalizing marijuana for teens is another aspect of the conversation.

In a 2017 report, the American Academy of Pediatrics (AAP) warns both doctors and parents that children need protection from the dangers of marijuana legalization in the United States. As the AAP points out, human brain development is ongoing until the mid-20s. Hence, marijuana use by adolescents can result in abnormal brain development.

In the report, the nation’s pediatricians stressed that marijuana use is far from harmless. In fact, teenage marijuana use can have an adverse and lasting effect on their physical and mental health. Moreover, parents’ use of marijuana colors their children’s attitudes. Sheryl A. Ryan, MD, FAAP, lead author of the clinical report and chairperson of the AAP Committee on Substance Use and Prevention, explains in the report:

“Parents who use marijuana themselves may not fully realize the effect this can have on their children. Seeing parents use marijuana makes kids more likely to use it themselves, whether or not their parents tell them not to, because actions speak louder than words.”

Hence, how parents react to the consequences of marijuana legalization matters. Teenagers and adolescents experience the impact of parental choices profoundly.

Newport Academy Substance Abuse Resources: effects of marijuana legalization

Understanding the Effects of Marijuana Legalization

Many experts believe that marijuana and teenagers do not make a healthy mix. Moreover, there is a misconception that marijuana is not addictive. In fact, researchers estimate that more than 4 million people in the United States currently meet the criteria for marijuana use disorder.

Examining this data, the National Institute on Drug Abuse (NIDA) conducted studies, revealing that 30 percent of those who use marijuana may have some degree of “marijuana use disorder.” Moreover, according to NIDA, teenagers are four to seven times more likely to develop this disorder than adults.

Furthermore, according to NIDA, marijuana potency has steadily increased over the past 30 years. Side by side with the impact of marijuana legalization, advances in technology have sent THC levels in the drug skyrocketing. In the early 1990s, the average THC content in confiscated marijuana samples was roughly 3.8 percent. In 2014, the THC content had risen dramatically, to 12.2 percent.

Why is THC content important? The higher the THC content, the more powerful the drug. Hence, the risk for marijuana addiction increases.

Statistics on Marijuana and Teenagers

In the age of legalization, teenagers are growing more tolerant and accepting of marijuana use. According to the National Survey on Drug Use and Health, conducted annually by the US Department of Health and Human Services, the percentage of 12- to 17-year-olds who perceive a “great risk” in smoking marijuana regularly (more than once a week) dropped from 55 percent in 2007 to 41 percent in 2015. In other words, a majority of teenagers do not see marijuana as a dangerous drug.

As a result, teenage marijuana use is at its highest level in more than 30 years. Teens in 2019 are more likely to use marijuana than tobacco. Also, teens resist treatment for marijuana abuse because they do not see it as a dangerous drug. Therefore, teens are more likely to experience the long-term negative consequences of marijuana legalization.

Professional Opinions on the Effects of Marijuana Legalization

In 2017, the American Academy of Child and Adolescent Psychiatry made a policy statement on marijuana legalization, as follows:

“The American Academy of Child and Adolescent Psychiatry (AACAP) advocates for careful consideration of potential immediate and downstream effects of marijuana policy changes on children and adolescents … Adolescents are especially vulnerable to marijuana’s many known adverse effects. One in six adolescent marijuana users develops cannabis use disorder, a well-characterized syndrome involving tolerance, withdrawal, and continued use despite significant associated impairments. Selective breeding has increased marijuana’s addictive potency and potential harm to adolescents. Heavy use during adolescence is associated with increased incidence and worsened course of psychotic, mood, anxiety, and substance use disorders.”

Overall, professional mental health organizations in the United States are opposed to the recreational legalization of marijuana. These medical organizations do not believe there has been enough research to declare marijuana a safe drug.

A Case Study: Effects of Marijuana Legalization in Colorado

Overall, teen marijuana use in Colorado only increased slightly after the state legalized the drug in 2014. However, the dangerous consequences of teenage marijuana use are becoming more evident. While government revenue has risen due to taxation on the new pot-selling industry, other costs are being paid.

Since marijuana was legalized in Colorado, there has been a significant increase in the state’s homeless population, in part as a result of the drug. Also, a large Colorado hospital reports a 15 percent increase in babies born with THC in their blood. Finally, marijuana-related hospitalizations have greatly increased, and marijuana-related poison control center calls in Colorado doubled in less than three years.

In addition, marijuana legalization has led to a rise in certain types of marijuana-related crime—in particular organized crime and illegal growing of pot. Of the 56 homicides in the city in 2017, Denver counts seven as marijuana related. Moreover, the US Attorney’s Office in Denver classified one-third of its 2017 marijuana cases as violent, with firearms regularly seized in marijuana busts.

Ray Padilla, the head of the Colorado Drug Investigators Association, describes the negative impact of legalization: “It’s out of control. We probably spend more assets on marijuana now than we ever did …I have encountered more weapons in marijuana locations than any other type of drug.” When Agent Padilla discusses marijuana locations, he refers to the places where illegal marijuana crops are both grown and sold.

Newport Academy Substance Abuse Resources: effects of marijuana legalization

How to Recognize Marijuana Use in Teenagers

Teens who are regularly using marijuana might show any or all of the following symptoms:

  • Talking loudly
  • Increased appetite
  • Red eyes
  • Forgetfulness
  • Sleepiness
  • Marijuana paraphernalia on their person or in their room
  • Scent of the drug on their clothes or in their room.

A full assessment from a mental health professional can help teens and parents struggling with substance abuse issues. Proactive choices and early treatment ensure the most beneficial outcomes for teens and their families.


American Academy of Pediatrics 

National Institute on Drug Abuse

American Academy of Child and Adolescent Psychiatry

Impacts of Marijuana Legalization in Colorado: Report Pursuant to Senate Bill 13283