A drugA name for a wide variety of chemical substances capable of altering the function of your mind and body in significant ways. These can include over the counter prescriptions, alcohol, and controlled substances. Most drugs are either physically and/or psychologically habit-forming. More used to treat opioidCompounds acting on opioid receptors in the body, whether naturally occurring or synthetic. Their use can lead to the development of crippling physical dependence. Whether used through a prescription for pain management or recreationally, its overuse in the United States has been classified as a nat... More addiction. It can also be prescribed for pain management.