Which concept describes withdrawal symptoms upon cessation of opioid use?

• A. Tolerance
• B. Addiction
• C. Overdose
• D. Physical dependence

Answer: (D)

Withdrawal symptoms when stopping opioids come from the body's physiological adaptation to the drug, called physical dependence. With chronic opioid use, the nervous system undergoes changes to counteract the drug’s effects. When the drug is suddenly removed, these adaptations produce withdrawal symptoms as the body readjusts back to baseline. This is different from tolerance, where higher doses are needed to achieve the same effect, and from addiction, which centers on compulsive use and cravings. Overdose is about dangerous toxicity from too much drug. So the situation described—withdrawal upon cessation—best fits physical dependence.