The Truth about Marijuana
Marijuana is a Schedule I controlled substance. It is commonly
grown in any climate that can sustain plant life. Marijuana can be
grown locally or smuggled into the United States from other source
countries.
Usually smoked as a cigarette or joint, or in a pipe or bong,
marijuana has appeared in "blunts" in recent years. These are
cigars that have been emptied of tobacco and refilled with
marijuana, sometimes in combination with another drug, such as
crack. Some users also mix marijuana into foods or use it to brew
tea.
The main active chemical in marijuana is THC
(delta-9-tetrahydrocannabinol). Short-term effects of marijuana use
include problems with memory and learning; distorted perception;
difficulty in thinking and problem-solving; loss of coordination;
and increased heart rate, anxiety, and panic attacks.
Health Hazards
Effects of Marijuana on the Brain. Researchers have
found that THC changes the way in which sensory information gets
into and is acted on by the hippocampus. This is a component of the
brain's limbic system that is crucial for learning, memory, and the
integration of sensory experiences with emotions and motivations.
Investigations have shown that THC suppresses neurons in the
information-processing system of the hippocampus. In addition,
researchers have discovered that learned behaviors, which depend on
the hippocampus, also deteriorate.
Effects on the Lungs. Someone who smokes marijuana regularly may
have many of the same respiratory problems that tobacco smokers
have. These individuals may have daily cough and phlegm, symptoms
of chronic bronchitis, and more frequent chest colds. Continuing to
smoke marijuana can lead to abnormal functioning of lung tissue
injured or destroyed by marijuana smoke.
Regardless of the THC content, the amount of tar inhaled by
marijuana smokers and the level of carbon monoxide absorbed are
three to five times greater than among tobacco smokers. This may be
due to marijuana users inhaling more deeply and holding the smoke
in the lungs.
Effects of Marijuana Use during Pregnancy. Research has shown that
babies born to women who used marijuana during their pregnancies
display altered responses to visual stimuli, increased
tremulousness, and a high-pitched cry, which may indicate problems
with neurological development. During infancy and preschool years,
marijuana-exposed children have been observed to have more
behavioral problems and to perform tasks of visual perception,
language comprehension, sustained attention, and memory more poorly
than non exposed children do. In school, these children are more
likely to exhibit deficits in decision-making skills, memory, and
the ability to remain attentive.
Effects of Heavy Marijuana Use on Learning and Social Behavior. A
study of college students has shown that critical skills related to
attention, memory, and learning are impaired among people who use
marijuana heavily, even after discontinuing its use for at least 24
hours. Researchers compared 65 "heavy users," who had smoked
marijuana a median of 29 of the past 30 days, and 64 "light users,"
who had smoked a median of 1 of the past 30 days. After a closely
monitored 19- to 24-hour period of abstinence from marijuana and
other illicit drugs and alcohol, the undergraduates were given
several standard tests measuring aspects of attention, memory, and
learning. Compared to the light users, heavy marijuana users made
more errors and had more difficulty sustaining attention, shifting
attention to meet the demands of changes in the environment, and in
registering, processing, and using information. The findings
suggest that the greater impairment among heavy users is likely due
to an alteration of brain activity produced by marijuana.
Longitudinal research on marijuana use among young people below
college age indicates those who used have lower achievement than
the nonusers, more acceptance of deviant behavior, more delinquent
behavior and aggression, greater rebelliousness, poorer
relationships with parents, and more associations with delinquent
and drug-using friends.
