Stimulant Use Disorder 563
Specifiers
“In a controlled environment” app lies as a further specifier of remission if the individual is
both in remission and in a controlled environm ent (i.e., in early remission in a controlled
environment or in sustained remission in a controlled environment). Examples of these
environments are closely supe rvised and substanc e-free jails, therapeutic communities,
and locked hospital units. 
Diagnostic Features
The amphetamine and amphetamine-type stimul ants include substances with a substi-
tuted-phenylethylamine struct ure, such as amphetamine, dextroamphetamine, and meth-
amphetamine. Also included are those substanc es that are structura lly different but have
similar effects, such as methylphenidate. These substances are usually taken orally or in-
travenously, although methamphetamine is also  taken by the nasal route. In addition to
the synthetic amphetamine-type compounds, th ere are naturally occurring, plant-derived
stimulants such as khât.  Amphetamines and other stimulants  may be obtained by prescrip-
tion for the treatment of obesity, attention-deficit/hyperactivity disorder, and narcolepsy.
Consequently, prescribed stimul ants may be diverted into the illegal market. The effects of
amphetamines and amphetamine-like drugs are sim ilar to those of cocaine, such that the
criteria for stimulant use disord er are presented here as a sing le disorder with the ability to
specify the particular stimulant used by the individual. Cocaine may be consumed in sev-
eral preparations (e.g., coca leaves, coca pa ste, cocaine hydrochloride, and cocaine alka-
loids such as freebase and crack) that differ in  potency because of varying levels of purity