Drug Abuse CPTAC The use of a drug for a reason other than which it was intended or in a manner or in quantities other than directed. Recreational Drug Use Drug Abuse Drug_Abuse Individual Behavior The use of illegal drugs or the use of prescription or over-the-counter drugs for purposes other than those for which they are meant to be used, or in large amounts. Drug abuse may lead to social, physical, emotional, and job-related problems. C16522 Drug Use Disorder Drug Abuse drug abuse C0013146 Substance Abuse