Which statement best differentiates drug dependence from tolerance?

• A. Dependence involves withdrawal symptoms when stopped; Tolerance involves needing larger doses for the same effect
• B. Tolerance involves withdrawal symptoms; Dependence involves needing larger doses
• C. They are the same concept
• D. Neither occurs with opioids

Answer: (A)

Differentiating dependence from tolerance hinges on how the body responds to stopping the drug versus how it responds to ongoing use. Tolerance means you need larger doses to achieve the same effect because the body adapts to the drug’s presence (receptor changes, diminished response). Dependence means the body has adapted to the drug such that stopping it produces withdrawal symptoms. With opioids, these processes often occur together, but the defining feature of dependence is withdrawal upon cessation, not simply needing more drug for the same effect.