| Addiction | Neurobiologic, multifactorial disease characterized by impaired control, compulsive drug use, and continued use despite harm |
| Physical dependence | Normal adaptive state that results in withdrawal symptoms if the drug is abruptly stopped or decreased |
| Pseudoaddiction | Relief-seeking behaviors misinterpreted as drug-seeking behaviors that resolve upon institution of effective analgesic therapy |
| Substance abuse | Use of any substance for purposes that are non-therapeutic or are not those for which it is prescribed |
| Tolerance | Physiologic state from regular drug use in which an increased dosage is needed to produce the same effect |