health

People can become addicted to a wide range of substances, including alcohol,
amphetamines, cocaine, heroin, inhalants*, LSD, marijuana*, morphine*,
tobacco, PCP, and sedatives*, just to name a few commonly abused drugs.

Marijuana addiction Some people believe that marijuana use is relatively
safe, because it does not lead to addiction. However, regular marijuana
users may become psychologically dependent on the drug. Some longtime,
heavy users also can experience mild signs of physical dependence, including
tolerance and withdrawal. Some studies suggest that marijuana affects
the brain’s reward system in much the same way as other addictive drugs.

Alcohol addiction Alcoholism (AL-ko-hall-i-zm) is the common name
for an addiction to alcohol. Some people with alcoholism develop a tolerance
that lets them drink large amounts of alcohol without seeming drunk or passing
out. Others have severe withdrawal symptoms if they stop drinking. Delirium
tremens (de-LEER-ee-um TRE-munz) is the name given to the most
severe withdrawal symptoms seen in people who have alcoholism. These
symptoms include confusion, disordered thoughts, and hallucinations*.

Tobacco addiction Cigarette smoking is a difficult habit to break,
because tobacco contains nicotine, a highly addictive substance. Smokers
can build up a tolerance for nicotine, as shown by the fact that most
smokers increase the number of cigarettes they smoke as they continue to
use tobacco. They also go through withdrawal when they are unable to
smoke, which explains why many smokers rush to light up as soon as they
leave a place where smoking is not allowed.

Caffeine addiction Caffeine (ka-FEEN), a substance found in coffee,
tea, colas, and many nonprescription medicines, is a widely used
mind-altering chemical. It is no accident that coffee, a potent source of
caffeine, is the favorite wake-up drink in so many homes. People often
use caffeine for the temporary surge of energy it produces, much like the
“buzz” that comes from some other drugs. Owing to tolerance, however,
it eventually takes more and more caffeine to get this feeling. When daily
coffee drinkers stop using caffeine, they may have withdrawal symptoms,
such as headaches, fatigue, and irritability.