Stimulant Use Disorder 565
among individuals in treatment occurs, on average, at approximately age 23 years. For pri-
mary methamphetamine–primary treatment admissions, the average age is 31 years.
Some individuals begin stimulant use to control weight or to improve performance in
school, work, or athlet ics. This includes obtaining medications such as methylphenidate or
amphetamine salts prescribed to others for the treatment of attention-deficit/hyperac-
tivity disorder. Stimulant use disorder can develop rapidly with intravenous or smoked
administration; among primary admissions fo r amphetamine-type stimulant use, 66% re-
ported smoking, 18% reported inje cting, and 10% reported snorting. 
Patterns of stimulant administration include episodic or daily (or almost daily) use.
Episodic use tends to be separated by 2 or more days of non-use (e.g., intense use over a
weekend or on one or more weekdays). “Bin ges” involve continuous high-dose use over
hours or days and are often associated with  physical dependence. Binges usually termi-
nate only when stimulant supplies are deplet ed or exhaustion ensues. Chronic daily use
may involve high or low doses, often with an increase in dose over time.
Stimulant smoking and intravenous use are a ssociated with rapid progression to se-
vere-level stimulant use disorder, often occu rring over weeks to months. Intranasal use of
cocaine and oral use of amphetamine-type stim ulants result in more  gradual progression
occurring over months to years. With continui ng use, there is a diminution of pleasurable
effects due to tolerance and an increase in dysphoric effects. 
Risk and Prognostic Factors