Andy was a freshman in high school when he first tried marijuana. He and his friends began experimenting, thinking marijuana was “cool and just like smoking a cigarette, only safer.” When a friend overdosed in sophomore year, Andy sank into a depression and increased his marijuana use. He dropped out of school in his junior year and began working full time in a variety of jobs. By age 23, Andy and his friends were experimenting with other drugs—heroin, in particular. By age 25, Andy was addicted to heroin, unemployed, and living on the streets.
Many consider marijuana to be safe. Recreational use of marijuana is legal in several states and the District of Columbia, and with many other states likely to legalize marijuana in the future. This article focuses primarily on the use of marijuana by adolescents because adolescents are strongly affected by marijuana use. Nurses are intimately involved in caring for adolescents in schools, other community settings, and mental health settings, as well as inpatient and correctional facilities. This underscores the importance of educating nurses fully about the scope of issues associated with marijuana use in this population.
Usage patterns among teens
Marijuana is the most commonly used illegal drug in America. It has more than 300 names, the most familiar being cannabis, weed, pot, and marijuana. After declining for 7 years (1999 through 2007), the number of high school students admitting to ever using marijuana or trying it before age 13 is now steadily increasing, according to the National Institutes of Health (NIH). Since 2009, the number of high school students who admitted to using marijuana one or more times, or on school property, has also increased. Based on findings from its ongoing study of students in grades 8, 10, and 12, the NIH reported that almost 44% of teens have tried marijuana by the time they graduate from high school. Marijuana use declined slightly among teens in 2014, but the number of students who disapproved of marijuana use or believed it was harmful also decreased. (See About marijuana.)
Marijuana is made from the dried leaves, stems, flowers, and seeds of cannabis and contains the mind-altering chemical delta-9-tetrahydrocannabinol (THC). It is smoked, brewed as tea, or mixed in food. Smoking is the fastest way to deliver THC to the brain, where it targets cannabinoid receptors. These receptors are part of the endocannabinoid system, which is activated by naturally occurring bodily chemicals and is important in normal brain development and functioning. Marijuana use varies, with heavy marijuana use most often classified as use of one or more joints per day.
As marijuana enters the brain, it acts on the areas with many cannabinoid receptors, which are predominately in areas of the brain that affect pleasure, memory, thinking, concentration, sensory/time perception, and coordinated movement. Marijuana can cause problems with learning and memory via its effect on the hippocampus. In the cerebellum, which controls coordination and balance, marijuana may impair physical functions (such as driving). Impaired judgment and control, as a result of marijuana’s effects on the frontal cortex, may lead to engaging in risky activities such as unprotected sex or criminal behavior.
Marijuana stimulates the brain cells to release dopamine and causes a feeling of euphoria (a high). Some individuals report a feeling of great relaxation, heightened sensory perception, altered time perception, and increased appetite. Others report feelings of anxiety, fear, distrust, or panic. Smoking effects are usually immediate, lasting as long as 3 hours. The high from ingesting cannabis usually occurs within 30 minutes to an hour and has been found to last over 4 hours. As the high dissipates, the person may feel sleepy or depressed. Withdrawal symptoms include anxiety, insomnia, irritability, and depression.
Potential side effects of marijuana use
The physiological side effects of marijuana have been difficult to delineate because it is frequently used concurrently with alcohol and nicotine. But there is evidence of an increased risk for bronchitis, emphysema, pneumonia, and lung cancer from smoking marijuana. Several factors may be associated with this: Marijuana contains the same carcinogens as tobacco, is inhaled more deeply than nicotine, and more of the tar and other carcinogens released from smoking marijuana are retained in the lungs.
Although the physiological mechanism underlying the cause is unknown, marijuana use has been associated with myocardial infarction (MI), stroke, transient ischemic attacks, and peripheral vascular disease. These cardiovascular effects may be linked to the effects associated with cannabis—transient vasoconstriction, tachycardia, and increased pulse rate, blood pressure, and systemic blood flow—which put an extra workload on the heart. Research by Thomas and colleagues suggests that the risk for MI in the hour after marijuana use was 4.8 times higher than average; mortality risk increased 4.2-fold in MI patients using cannabis in the preceding week.
The concentration of delta-9-tetrahydrocannabinol (THC), the main psychoactive constituent of marijuana, has increased from about 4% in the 1980s to close to 15% in 2012, according to government health agencies. Although the effects of higher THC potency are not completely understood, there appears to be a greater possibility for adverse or unpredictable reactions, especially in new users, and a greater risk for addiction in regular users.
The data about the association between marijuana use and an increase in psychosis are contradictory. But marijuana has been linked to an increase in anxiety and paranoia, and heavy marijuana use has been linked to increased suicidal ideation in male adolescents.
Reports indicate that even occasional, light users of marijuana are more likely to report poorer health, to engage in violence and crime, and are less likely to graduate from college. Marijuana is increasingly being identified as the cause of motor vehicle accidents (MVAs). In 2013, 23.4% of high school seniors admitted to driving under the influence of marijuana, an increase of over 11% since 2011. Studies have found that marijuana use increases MVAs, and an increase in cannabis use is predicted to increase the number of MVA injuries and fatalities.
More conclusive research about prenatal exposure to marijuana is needed. It has been estimated that marijuana is used by 9% to 27% of pregnant women. Urine testing for THC suggests the use of marijuana in pregnant women may be higher. Marijuana exposure prenatally has not been found to cause fetal deformity and birth defects, but it does have a very detrimental effect on the developing fetal brain and has been linked to changes in adolescent behavior. Although women often stop or reduce their intake of marijuana once they know they are pregnant, the damage occurs, especially during the first trimester when women may not even know they are pregnant.
Longitudinal studies have found that prenatal exposure to marijuana is not innocuous. Marijuana has significant lifelong effects on children, particularly developmental delays and learning and behavioral problems associated with executive function. (See Effects of marijuana on executive function.)
Effects of marijuana on executive function
Executive function processes occur in the brain’s frontal cortex and are important to attention, memory, and motor skills. Goal-directed activities such as planning, organizing, strategizing, awareness, remembering details, and managing time and space are all part of executive function.
Brain development occurs at a rapid rate both prenatally and throughout adolescence. Lasting neurodevelopmental vulnerability is associated with cannabis exposure at these critical times, causing problems with executive function.
Children exposed to marijuana prenatally may have problems with executive function, expressed as difficulty sitting still, remembering to do homework, or remembering information. Executive function involves integrating life experiences with present actions. If children have difficulty with executive function in early years, they often experience problems with school and with relationships that carry over into adolescence, when these problems can be compounded by normal adolescent characteristics such as labile emotions, lack of impulse control, need for peer approval, and the search for independence. The use of cannabis in adolescence impacts brain development further, potentially putting teens at higher risk for additional school, home, work, and community problems at this time of great physical and emotional change.
Even in infancy, differences in brain activity and sleeping patterns have been noted in children who were exposed to marijuana prenatally. At age 3, such children had problems with impulse control and ability to stay on task, which continued when the children were studied at ages 6, 9, and into adolescence. At age 14, adolescents exposed to marijuana prenatally were more likely to be involved in delinquent behavior. Although observed more often in children of mothers who were heavy users of marijuana, these effects occurred even in children whose mothers smoked less often.
Marijuana use has been found to be higher in males ages 18 to 29 and among individuals reporting any lifetime psychiatric disorder, attention deficit hyperactivity disorder, or mood or anxiety disorder, according to an article by Lopez and colleagues. Adolescents prenatally exposed to marijuana are more likely to use the drug. Although the evidence regarding marijuana use based on ethnicity differs, studies suggest higher marijuana use and dependence in minority groups. Low-income youth are more likely to use marijuana as an entry drug, which may be because it is less expensive than cigarettes.
Government researchers found that 35% of high school seniors admitted ongoing marijuana use, with 21.2% admitting using marijuana in the past 30 days. More teens admitted smoking marijuana (23%) than cigarettes (19%) because they believed it was safer. If marijuana were legalized, 10% of nonusers said they would use it and 18% of users said they would increase its use.
These numbers are important because regular marijuana use by young people disrupts thinking ability and memory. This may be long-lasting or permanent, depending on the neuromaturation processes occurring in the adolescent brain. Marijuana users who began using the drug in adolescence show abnormal changes in the cortex, with markedly reduced connectivity among areas responsible for learning and memory.
Regular users of marijuana have altered prefrontal cortical development, which controls decision making, social cognition, inhibition control, and other behavior-related factors, putting them at risk for behavior deviating from social and legal norms. A large, longitudinal New Zealand study showed that people who began smoking marijuana heavily in their teens lost an average of 8 IQ points between ages 13 and 38, which were not fully restored, even in those who quit smoking marijuana as adults. Students who smoke marijuana are less likely to finish high school and have a higher risk for unemployment, risky behavior, aggression, criminal behavior, and suicide.
Potential gateway drug
Marijuana decreases dopamine neuron reactivity in adolescent rats. Dopamine controls reward regions in the brain, and seems to prime the brain for heightened responses to other drugs. This could explain teens’ urge to smoke repeatedly to reproduce the high afforded by cannabis and/or to re-create it with other drugs. About one in six people who start using marijuana as teens have trouble controlling their use of it, and many smoke every day. Humans develop a tolerance and addiction to marijuana, especially long-term users. This puts those who begin marijuana use in adolescence at risk for addiction. A NIH-sponsored study of 6,624 individuals who used cannabis as their first drug, found that almost 45% progressed to other illegal drugs. Users aged 15 to 45 were more likely to advance to dependence.
Implications for nursing
Touching the lives of millions every day as we do, nurses are in a unique position to affect the way the national debate progresses on the legalization of recreational marijuana. The diversity of nursing practice affords us the opportunity to affect the conversation and educate the public and healthcare professionals alike. By staying current with the latest literature, and discussing the latest evidence-based information with nursing colleagues and other healthcare professionals, we can begin to fully understand the impact of cannabis on adolescent health and work together to make a difference.
Nurses work with children and adolescents in a variety of settings and can identify gaps in the literature regarding marijuana safety. Nurses can initiate independent research and collaborate with nurse researchers or with other professionals, such as mental health and substance abuse experts, to conduct interprofessional research.
Nurses in academic settings can initiate discussions with student nurses and other disciplines to help understand the biopsychosocial effects of marijuana and the implications of legal recreational marijuana on different populations. Nurses in higher education are in a perfect position to encourage their students to investigate this topic for their doctoral research and capstone projects.
Nurses are the main providers of health education. As such, we are in a perfect position to interact with and discuss the effects of cannabis with high-risk groups.
- School nurses interact with youth every day. Although nurses are not always intimately involved in curriculum or program development, they can provide professional input into developing programs on drug abuse and its potential effects. Building relationships with students who trust the nurse will make it more likely that they’ll turn to the nurse in times of stress. By educating faculty about the effects of marijuana on youth, nurses will help create a team of supportive, caring adults to educate and protect children as they progress through difficult life stages and situations.
- By discussing recreational marijuana use with high-risk groups such as young women of child-bearing age and adolescents from high-risk groups, nurses can change lives. Just as nurses became involved in educating the public about the risks of low folic acid and its effect on the fetus, we can educate about the risk to youth if marijuana is legalized—not just its use, but also about the message that legalization brings to youth that marijuana is harmless.
- Nurses can initiate and be involved in prevention programs. We can help teens begin peer-support groups, which have been effective in helping adolescents avoid and reduce high-risk behaviors.
Law-enforcement and healthcare professionals have been working together in many communities to provide rehabilitation and support, rather than incarceration, for youth accused of crimes involving drugs (including marijuana). Nurses who work with at-risk youth have an opportunity to replicate these programs in their communities. We can stay active in professional nurses’ organizations, through which we can educate public officials and others about the effects of marijuana on adolescents and others. And, yes, we vote!
More topics concerning marijuana and adolescents should become part of the nursing literature. Nurses can better share their knowledge about marijuana and adolescents with other nurses by publishing in nursing journals.
Many topics are beyond the scope of this article. Some questions that we were not able to explore fully in this article include:
- Can recreational marijuana be decriminalized without legalizing it?
- What is the best way to educate women of child-bearing age about the potential dangers of prenatal exposure to marijuana?
- How can we protect and educate vulnerable populations about marijuana, especially minority adolescents and youth living in high-risk situations?
- What can nurses do to address the needs of at-risk youth already suffering from the consequences of prenatal or adolescent exposure to marijuana?
Nurses are vital advocates for the protection and education of adolescent health and can play an important role in the creation of programs and policies concerning marijuana. We must exchange this information: What programs have you been involved in that worked—or did not work—to educate vulnerable adolescents about marijuana? Nurses can and must advance the success of programs preventing marijuana use among adolescents
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Robert White is an assistant professor of nursing at Rutgers University in Newark, New Jersey, and Eileen Helbig Toughill is an associate professor of nursing at Seton Hall University in South Orange New Jersey.