• Drug use: intentional use of a mind-altering substance for any reason.• Drug misuse: unintentional or inappropriate use of prescribed or over-the-counter drugs (ex., using cough syrup to get high).• Drug abuse: the intentional and inappropriate use of a drug resulting in physical, emotional, financial, social, or intellectual consequences (ex., regularly using cough syrup to get high and committing crimes in order to procure cough syrup)