legalization, laws in every state still prohibit teens
from possessing or using marijuana for recreation.
Virginia law, for example, carries a penalty for anyone
under 21 years of age found in possession of marijuana or
marijuana products in public.
So why has daily marijuana use increased significantly
among middle school and young high school students since
Efforts to legalize marijuana across the country and
the mixed media messages of popular culture promulgated
through television, music, and the internet are spreading
the misperception that marijuana is a harmless, all
natural, non-addictive substance with no serious side
According to Dr. Susan Weiss, a scientist at the
National Institute on Drug Abuse (NIDA), studies on
adolescent behavior have found that as teens’
perception of risk decreases, their risk take behavior,
i.e., marijuana use, increases.
What is marijuana?
Marijuana is Cannabis. It is made up of seeds, leaves,
flowers, and stems from the cannabis plant. People use it
in several forms, including dried and smoked, vaped, or
ingested in baked goods. Marijuana contains over 400
hundred chemicals. Two main chemicals are
non-psychoactive CBD (Cannabidiol) and psychoactive THC
(Delta-9-tetrahydrocannbidio). Research studies show
that, while CBD is non-addictive and non-intoxication,
THC, however, is addictive and can have adverse
effects on the brain.
How does marijuana work?
In the 1990s, scientists discovered a biological
system in the brain called the endocannabinoid system.
This system consists of three parts: endocannabinoids,
cellular receptors, and enzymes. When brain cells receive
messages from other cells, they release endocannabinoids
that bind to cellular receptors acting as an “off
switch” that lets cells know the message has been
received. Enzymes eventually break down the
endocannabinoids, and the cycle repeats itself.
Endocannabinoids are critical to creating balance in the
brain and regulating functions such as memory, motor
skills, and emotions.
When THC enters the brain, it inhibits the normal
function of the endocannabinoid system by binding to cell
receptors. It then causes a release of dopamine creating
a “high” or a feeling of pleasure that people
get from marijuana. Dopamine helps the brain remember the
pleasurable experience, and over time it trains the brain
to seek out drugs over other experiences that produce
feelings of reward. The pleasurable feelings created by
the release of dopamine is one reason people use
marijuana repeatedly, which can lead to addiction. The
developing adolescent brain relies heavily on the reward
center of the limbic system, which makes teens more
sensitive to the effects of dopamine and at greater risk
Short and Long-term Consequences of Marijuana
In addition to the risk of addiction, marijuana use
leads to other short- and long-term consequences.
Short-term effects from marijuana use include feelings of
relaxation or demotivation; increased heart rate; loss of
coordination and slower reaction times; altered sense of
time; increased appetite; and feelings of anxiety, fear,
distrust, and panic. Marijuana use over a long period of
time can cause respiratory problems and make it difficult
to retain and process information.
Marijuana use among teens increases the risk of
academic and athletic failure. THC impacts the
hippocampus, a part of the brain responsible for
cognitive functions including attention, critical
thinking, processing, and storing new information.
Impaired focus and concentration have serious
implications for student learning and achievement. In
addition, marijuana use among teens has also been linked
to lack of motivation, which may be the cause for school
absences and drop-out rates.
THC also affects parts of the brain that control motor
skills such as reflexes and coordination, which are
critical for athletic performance. Even cognitive and
motor functions that are diminished for a short period of
time can increase the risk of a serious injury, which has
implications for youth sport concussions.
Academic and athletic performance are not the only
areas affected by marijuana use. Many teens will learn to
drive an automobile during their adolescent years, which
makes safe driving a serious concern. The same
capabilities that teens need to perform well in school
and in sports, such as concentration, critical thinking,
and motor skills are the same skills necessary for safe
driving. THC impairs these functions and can increase the
risk of a car accident.
Common misconceptions about marijuana and increased
use among youth has created a public health concern.
Schools have a responsibility to educate students about
the facts and urge them to abstain while in school and
delay the onset of use until adulthood.