Tolerance is a reduced res ponsiveness to the effect of any drug, which necessitates larger doses to achieve an equivalent effect of the initial dose. Pseudoaddiction(假性成瘾)is a term used to describe the iatrogenic (医源性)syndrome of drug-seeking behavior that develops as a direct consequence of inadequate pain management.Physical dependence refers to the state in which an individual must take the substance to feel physically normal; not taking the drug results in withdrawal symptoms. Psychological dependence refers to an individual's need to derive(派生) an alternation in mood from a substance.