Stimulants is a name given to several groups of drugs that tend to increase alertness and physical activity. The groups include pharmaceuticals such as amphetamines and the street drugs commonly called "uppers" or "speed," and cocaine.

The more widely abused stimulants are amphetamines and cocaine. Cocaine has limited commercial use and its sale and possession are strictly controlled. Amphetamines are sometimes prescribed by physicians, and their availability makes them prime candidates for misuse.

Used properly, amphetamines increase alertness and physical ability. They are often prescribed to counter the effects of narcolepsy, a rare disorder marked by episodes of uncontrollable sleep, and to help children with minimal brain dysfunction.

Amphetamines increase the heart and respiration rates, increase blood pressure, dilate the pupils of the eyes, and decrease appetite. Other side effects include anxiety, blurred vision, sleeplessness, and dizziness. Abuse of amphetamines can cause irregular heartbeat and even physical collapse. A common form of abuse of amphetamines is by people who use them to counter the effects of sleeping pills (barbiturates) taken the night before. This roller coaster effect is damaging to the body.

While amphetamine users may feel a temporary boost in self-confidence and power, the abuse of the drug can lead to delusions, hallucinations, and a feeling of paranoia. These feelings can cause a person to act in bizarre fashion, even violently. In most people, these effects disappear when they stop using the drug.

Amphetamines are stolen or acquired through scams involving pharmacists or physicians who are duped into writing prescriptions for the drugs. These illegally acquired drugs are either sold as is or reduced to yellowish crystals that can be ingested in a number of ways, including sniffing and by injection.

Another means of illegal sale of amphetamines involves "look-alike" drugs produced in illicit laboratories. One danger in these look-alikes is that the potency may vary from batch to batch. A person accustomed to using a weak look-alike may unwittingly suffer an overdose taking the same volume of a stronger look-alike.


Amphetamines are psychologically addictive. Users become dependent on the drug to avoid the "down" feeling they often experience when the drug's effect wears off. This dependence can lead a user to turn to stronger stimulants such as cocaine, or to larger doses of amphetamines to maintain a "high".

People who abruptly stop using amphetamines often experience the physical signs of addiction, such as fatigue, long periods of sleep, irritability, and depression. How severe and prolonged these withdrawal symptoms are depends on the degree of abuse.

That boost we get from that morning cup of coffee is the result of the caffeine that naturally occurs in coffee. Caffeine is a common stimulant and is found not only in coffee and tea, but also in soft drinks and other foods. It can also be bought over-the-counter in tablet form. Too much caffeine can cause anxiousness, headaches, and the "jitters." Caffeine is also addictive and a person who abruptly stops drinking coffee may experience withdrawal symptoms.

Want more information? For copies of the following publications, contact:

National Clearing House for Drug and Alcohol Information
P.O. Box 2345
Rockville, MD 20847-2345

CAP 35	NIDA Capsule: Methamphetamine Abuse.  2 pp.
M 115	Methamphetamine Abuse: Epidemiologic Issues and Implications.
              NIDA Research Monograph 115.  130 pp.
M 94	Pharmacology and Toxicology of Amphetamine-Related Designer Drugs.
              NIDA Research Monograph 94.  365 pp.

Go to FACT Sheet List

Division of Alcohol and Drug Abuse
1706 East Elm; P.O. Box 687
Jefferson City, Missouri 65102