Methamphetamine is a very addictive stimulant drug that activates
certain systems in the brain.
It is chemically related to amphetamine
but, at comparable doses, the effects of methamphetamine are much more
potent, longer lasting, and more harmful to the central nervous system
Methamphetamine is a Schedule II stimulant, which means it has a high
potential for abuse and is available only through a prescription that
cannot be refilled. It can be made in small, illegal laboratories,
where its production endangers the people in the labs, neighbors, and
the environment. Street methamphetamine is referred to by many names,
such as "speed," "meth," and "chalk." Methamphetamine hydrochloride,
clear chunky crystals resembling ice, which can be inhaled by smoking,
is referred to as "ice," "crystal," "glass," and "tina."
Methamphetamine is taken orally, intranasally (snorting the powder), by
needle injection, or by smoking. Abusers may become addicted quickly,
needing higher doses and more often. At this time, the most effective
treatments for methamphetamine addiction are behavioral therapies such
as cognitive behavioral and contingency management interventions.
increases the release of very high levels of the neurotransmitter
dopamine, which stimulates brain cells, enhancing mood and body
movement. Chronic methamphetamine abuse significantly changes how the
brain functions. Animal research going back more than 30 years shows
that high doses of methamphetamine damage neuron cell endings.
Dopamine- and serotonin-containing neurons do not die after
methamphetamine use, but their nerve endings ("terminals") are cut
back, and regrowth appears to be limited. Noninvasive human brain
imaging studies have shown alterations in the activity of the dopamine
system. These alterations are associated with reduced motor speed and
impaired verbal learning. Recent studies in chronic methamphetamine
abusers have also revealed severe structural and functional changes in
areas of the brain associated with emotion and memory, which may
account for many of the emotional and cognitive problems observed in
chronic methamphetamine abusers.
small amounts of methamphetamine can result in increased wakefulness,
increased physical activity, decreased appetite, increased respiration,
rapid heart rate, irregular heartbeat, increased blood pressure, and
hyperthermia. Other effects of methamphetamine abuse may include
irritability, anxiety, insomnia, confusion, tremors, convulsions, and
cardiovascular collapse and death. Long-term effects may include
paranoia, aggressiveness, extreme anorexia, memory loss, visual and
auditory hallucinations, delusions, and severe dental problems.
Also, transmission of HIV and hepatitis B and C can be a consequence of
methamphetamine abuse. Among abusers who inject the drug, infection
with HIV and other infectious diseases is spread mainly through the
re-use of contaminated syringes, needles, and other injection equipment
by more than one person. The intoxicating effects of methamphetamine,
however, whether it is injected or taken other ways, can alter judgment
and inhibition and lead people to engage in unsafe behaviors.
Methamphetamine abuse actually may worsen the progression of HIV and
its consequences; studies with methamphetamine abusers who have HIV
indicate that the HIV causes greater neuronal injury and cognitive
impairment compared with HIV-positive people who do not use drugs.
Source: The National Institute on Drug Abuse (NIDA)