In reference to the central nervous system, any agent that activates, enhances, or increases neural activity; also called psychostimulant. Included are the amphetamines (amphetamines), cocaine, caffeine and other xanthines, nicotine, and synthetic appetite suppressants such as phenmetrazine or methylphenidate. Other drugs have stimulant actions which are not their primary effect but which may be manifest in high doses or after chronic use; they include antidepressants, anticholinergics, and certain opioids.
Stimulants can give rise to symptoms suggestive of intoxication, including tachycardia, pupillary dilatation, elevated blood pressure, hyperreflexia, sweating, chills, nausea or vomiting, and abnormal behaviour such as fighting, grandiosity, hypervigilance, agitation, and impaired judgement. Chronic misuse commonly induces personality and behaviour changes such as impulsivity, aggressivity, irritability, and suspiciousness. A full-blown delusional psychosis may occur. Cessation of intake after prolonged or heavy use may produce a withdrawal syndrome, with depressed mood, fatigue, sleep disturbance, and increased dreaming.
In ICD-I0, mental and behavioural disorders due to use of stimulants are subdivided into those due to the use of cocaine (ICD-10 F14) and those due to the use of other stimulants, including caffeine (ICD-10 F15). Prominent among them are amphetamine psychosis and cocaine psychosis. See also: psychotic disorder, alcohol- or drug-induced