Final answer:
Tolerance is the term used to describe when a drug user needs an increasing dose of a drug to achieve the same effect. It is linked to physiological dependence and can lead to an escalating cycle of drug use.
Step-by-step explanation:
Tolerance is the term used to describe the situation where a drug user needs an increasing dose of a drug to achieve the same effect. This means that over time, the user becomes less responsive to the drug and needs higher amounts to experience the desired effect. Tolerance is linked to physiological dependence, which is a condition where the body becomes accustomed to the presence of the drug and experiences withdrawal symptoms when the drug is discontinued. This can lead to an escalating cycle of drug use.