After chronic opioid use, why does abruptly stopping medication cause withdrawal symptoms such as anxiety and muscle pain?

💡 Explanation

Withdrawal occurs because chronic opioid use causes downregulation of dopamine receptors to maintain homeostasis. Therefore, abruptly stopping the opioid results in decreased dopamine signaling and resultant withdrawal symptoms. This is distinct from increased endorphin or altered glutamate transmission, rather than the direct impact on dopamine.

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