Why does chronic opioid use lead to escalating drug-seeking behavior, despite declining euphoric effects, within the brain's reward circuit?

💡 Explanation

Synaptic plasticity, a feature of neural circuits, causes long-term potentiation in the nucleus accumbens following repeated opioid exposure. This strengthens the association between drug-related cues and reward, therefore craving increases regardless of the drug's diminishing effects, rather than direct receptor changes or neurotransmitter saturation.

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