"Amphetamines are CNS stimulants and are used both medicinally and as drugs of abuse. Amphetamines are generally taken recreationally and to enhance performance (e.g., truck drivers staying awake). Ecstasy falls within this category, and as a methylated amphetamine derivative it also has hallucinogenic properties. Amphetamines have been associated with crash occurrence and could logically be associated with driving impairment both in the stimulation and withdrawal stages; in the latter case especially as the drug interacts with fatigue."


Lacey, John H.; Kelley-Baker, Tara; Furr-Holden, Debra; Voas, Robert B.; Romano, Eduardo; Ramirez, Anthony; Brainard, Katharine; Moore, Christine; Torres, Pedro; and Berning, Amy , "2007 National Roadside Survey of Alcohol and Drug Use by Drivers," Pacific Institute for Research and Evaluation (Calverton, MD: National Highway Traffic Safety Administration, December 2009), p. 26.