ABSTRACT
INTRODUCTION Stimulants (or psychomotor stimulants) may be defined as central nervous system (CNS) sympathomimetic agents which, in moderate oral doses, produce an elevation of mood, a sense of increased energy and alertness, decreased appetite, and enhanced performance in tasks that have been impaired by fatigue or boredom. The subjective effects of the prototype stimulants (amphetamine and cocaine) resemble effects of other stimulants when equated for differences in potency [19]. These drugs include dextroamphetamine (d-amphetamine), methamphetamine, phenmetrazine, methylphenidate, pemoline, diethylpropion, and cathinone. Stimulants are indicated clinically for treatment of narcolepsy and attention-deficit hyperactivity disorder (ADHD), but they are often used inappropriately without medical supervision to suppress appetite, decrease sleepiness, increase concentration, enhance physical performance, or simply for the sake of the stimulantinduced ‘‘high’’ or sense of increased energy and well-being. The intrinsic reinforcing effects of stimulants can lead to compulsive self-administration and dependence. With repetitive use, or at higher doses, these drugs are known to induce stereotypic movements and occasionally to elicit or exacerbate a variety of other movement disorders ranging from tics to dystonia, and transient parkinsonism following acute cessation of a chronic cocaine regimen.
