What is sensitization in the context of substance use?

What is sensitization in the context of substance use?

• A. Decreased brain response to a drug over time
• B. Amplified brain response to a drug or drug-related stimuli over time, leading to compulsive seeking and relapse
• C. Tolerance
• D. Withdrawal

Answer: (B)

Sensitization means that with repeated drug exposure, the brain becomes more responsive to the drug itself and to cues associated with it. This heightened sensitivity grows over time, so the same amount of drug or the same drug-related cues can provoke stronger craving, motivation, and drug-seeking behavior, which raises the risk of relapse even after periods of abstinence. This is distinct from tolerance, where the brain’s response to the drug diminishes with repeated use, requiring more of the drug to achieve the same effect. It’s also different from withdrawal, which involves negative symptoms that occur when the drug is no longer in the body. In sensitization, the underlying neuroadaptations in reward pathways—especially dopaminergic circuits—lead to amplified responses to both the drug and associated cues, making compulsive seeking more likely over time.

Sensitization means that with repeated drug exposure, the brain becomes more responsive to the drug itself and to cues associated with it. This heightened sensitivity grows over time, so the same amount of drug or the same drug-related cues can provoke stronger craving, motivation, and drug-seeking behavior, which raises the risk of relapse even after periods of abstinence. This is distinct from tolerance, where the brain’s response to the drug diminishes with repeated use, requiring more of the drug to achieve the same effect. It’s also different from withdrawal, which involves negative symptoms that occur when the drug is no longer in the body. In sensitization, the underlying neuroadaptations in reward pathways—especially dopaminergic circuits—lead to amplified responses to both the drug and associated cues, making compulsive seeking more likely over time.