In substance use disorders, which neurotransmitter change is described?

In substance use disorders, which neurotransmitter change is described?

• A. Increase in opioid peptides
• B. Decrease in opioid neuropeptides
• C. Increase in serotonin
• D. Decrease in dopamine

Answer: (B)

Chronic exposure to drugs produces neuroadaptive changes in the brain’s reward system, including the endogenous opioid system. With repeated drug use, there is a downregulation of opioid neuropeptides (like endorphins and enkephalins) and reduced opioid signaling. This diminished opioid tone contributes to negative mood, dysphoria, and craving during withdrawal, helping drive continued use to relieve that state. That’s why a decrease in opioid neuropeptides is the best description for neurotransmitter changes in substance use disorders. In contrast, increasing endogenous opioid peptides would imply greater opioid signaling, which doesn’t fit the withdrawal/dependence picture. Serotonin changes and dopamine shifts are also involved in addiction, but the classic description highlighted here focuses on reduced endogenous opioids as a key adaptive change.

Chronic exposure to drugs produces neuroadaptive changes in the brain’s reward system, including the endogenous opioid system. With repeated drug use, there is a downregulation of opioid neuropeptides (like endorphins and enkephalins) and reduced opioid signaling. This diminished opioid tone contributes to negative mood, dysphoria, and craving during withdrawal, helping drive continued use to relieve that state. That’s why a decrease in opioid neuropeptides is the best description for neurotransmitter changes in substance use disorders.

In contrast, increasing endogenous opioid peptides would imply greater opioid signaling, which doesn’t fit the withdrawal/dependence picture. Serotonin changes and dopamine shifts are also involved in addiction, but the classic description highlighted here focuses on reduced endogenous opioids as a key adaptive change.