Stimulants are drugs that stimulate the activity of the central nervous
system.
Stimulants are often referred to as "uppers" because they increase or speed up
mental and physical processes in the body. Some are prescribed medically to
increase alertness and physical activity.
Stimulants include nicotine (found in tobacco products), caffeine,
amphetamines, ecstasy, and cocaine.
Stimulants can give rise to symptoms suggestive of intoxication, including
abnormally rapid heart rate, dilatation of the pupils, elevated blood pressure,
overactive reflexes, sweating, chills, nausea or vomiting, and abnormal
behaviour such as fighting, hypervigilance, agitation, feelings of superiority,
and impaired judgement. Chronic misuse commonly induces personality and
behaviour changes such as impulsivity, aggressivity, irritability, and
suspiciousness.
Cessation of intake after prolonged or heavy use may produce a withdrawal
syndrome, with depressed mood, fatigue, sleep disturbance, and increased
dreaming.
