Stimulants are sometimes referred to as "uppers" and reverse the effects of fatigue on both mental and physical tasks. Two commonly used stimulants are nicotine, found in tobacco products, and caffeine, an active ingredient in coffee, tea, some soft drinks and many non-prescription medicines. Used in moderation, these substances tend to relieve malaise and increase alertness. Although the use of these products has been an accepted part of our culture, the recognition of their adverse effects has resulted in a proliferation of caffeine-free products and efforts to discourage cigarette smoking.

A number of stimulants, however, are under the regulatory control of the CSA. Some of these controlled substances are available by prescription for legitimate medical use in the treatment of obesity, narcolepsy and attention deficit hyperactivity disorders. As drugs of abuse, stimulants are frequently taken to produce a sense of exhilaration, enhance self esteem, improve mental and physical performance, increase activity, reduce appetite, produce prolonged wakefulness, and to "get high." They are recognized as among the most potent agents of reward and reinforcement that underlie the problem of dependence.

Stimulants are both diverted from legitimate channels and clandestinely manufactured exclusively for the illicit market. They are taken orally, sniffed, smoked and injected. Smoking, snorting or injecting stimulants produces a sudden sensation known as a "rush" or a "flash." Abuse is often associated with a pattern of binge use, that is, consuming large doses of stimulants sporadically. Heavy users may inject themselves every few hours, continuing until they have depleted their drug supply or reached a point of delirium, psychosis and physical exhaustion. During this period of heavy use, all other interests become secondary to recreating the initial euphoric rush. Tolerance can develop rapidly, and both physical and psychological dependence occur. Abrupt cessation, even after a weekend binge, is commonly followed by depression, anxiety, drug craving and extreme fatigue ("crash").

Therapeutic levels of stimulants can produce exhilaration, extended wakeulness and loss of appetite. These effects are greatly intensified when large doses of stimulants are taken. Physical side effects--including dizziness, tremor, headache, flushed skin, chest pain with palpitations, excessive sweating, vomiting and abdominal cramps--may occur as a result of taking too large a dose at one time or taking large doses over an extended period of time. Psychological effects include agitation, hostility, panic, aggression and suicidal or homicidal tendencies. Paranoia, sometimes accompanied by both auditory and visual hallucinations, may also occur. In overdose, unless there is medical intervention, high fever, convulsions and cardiovascular collapse may precede death. Because accidental death is partially due to the effects of stimulants on the body's cardiovascular and temperature-regulating systems, physical exertion increases the hazards of stimulant use.