College students and abuse of adderall

Race/Ethnicity and Gender Differences in Drug Use and Abuse Among College Students

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2377408/

You are able to distinguish the use of the illicit drugs within a study that was conducted on college students. One was the abuse on Adderall. 

Prevalence of Illicit Use and Abuse of Prescription Stimulants, Alcohol, and Other Drugs Among College Students: Relationship with Age at Initiation of Prescription Stimulants