A person who routinely misuses a substance and requires increasing amounts to achieve the same effect is experiencing:

A person who routinely misuses a substance and requires increasing amounts to achieve the same effect is experiencing:

• A. Dependence
• B. Tolerance
• C. Withdrawal
• D. Addiction

Answer: (B)

The main idea here is pharmacologic tolerance. When someone uses a substance repeatedly, the body adapts and becomes less responsive to the drug. This can happen through changes like enzymes that break down the drug more quickly or receptors that become less sensitive. Because of this reduced effect, the person needs larger doses to achieve the same level of feeling or relief. That escalating use reflects tolerance. This differs from dependence, which is about the body's adjustment that leads to withdrawal symptoms if the drug is stopped. Withdrawal is not about needing more to feel the effect. Addiction refers to compulsive use despite harm and loss of control, which can occur with or without tolerance. The specific pattern described—needing increasing amounts to obtain the same effect—points to tolerance.

The main idea here is pharmacologic tolerance. When someone uses a substance repeatedly, the body adapts and becomes less responsive to the drug. This can happen through changes like enzymes that break down the drug more quickly or receptors that become less sensitive. Because of this reduced effect, the person needs larger doses to achieve the same level of feeling or relief. That escalating use reflects tolerance.

This differs from dependence, which is about the body's adjustment that leads to withdrawal symptoms if the drug is stopped. Withdrawal is not about needing more to feel the effect. Addiction refers to compulsive use despite harm and loss of control, which can occur with or without tolerance. The specific pattern described—needing increasing amounts to obtain the same effect—points to tolerance.