Types of Psychoactive Drugs
Drugs like alcohol, marijuana, and cocaine affect the brain. Drugs that affect the brain
are calledpsychoactive drugs. They influence how a person feels, thinks, or acts. You
can watch animations of psychoactive drugs and the brain athttp://www.pbs.org/wnet/
closetohome/science/html/animations.html.
If you think you have never used a psychoactive drug, think again. Do you drink soft drinks,
such as colas? Most of them contain caffeine, which is a psychoactive drug. Caffeine is also
found in coffee and chocolate (Figure20.38).
Figure 20.38: All three of these popular products contain the stimulant drug caffeine. ( 1 )Caffeine is an example of a class of psychoactive drugs called stimulant drugs. Other classes
of psychoactive drugs are depressant drugs and hallucinogenic drugs. Drugs are classified
based on how they affect the nervous system.
- Astimulant drugis a psychoactive drug that speeds up the nervous system. This
type of drug may make people feel more alert. Stimulants also increase heart rate and
blood pressure. High doses of stimulant drugs can be dangerous. They can even cause
death. Other stimulant drugs include nicotine (in tobacco) and cocaine. - Adepressant drugis psychoactive drug that slows down the nervous system. This
type of drug may make people feel calm and drowsy. It also decreases heart rate and
the rate of breathing. High doses of depressant drugs can be dangerous. They may
slow down the nervous system so much that heartbeat and breathing stop. Examples
of depressant drugs include alcohol and morphine. - Anhallucinogenic drugis a psychoactive drug that can cause strange sensations,
perceptions, and thoughts. Examples of hallucinogenic drugs include marijuana and
LSD.
Drug Abuse
Psychoactive drugs, both legal and illegal, are often abused. Drug abuseis the use of a
drug without the advice of a doctor or for reasons other than those for which the drug was