National Certified Addiction Counselor, Level I (NCAC I) Practice Exam 2025 – Comprehensive All-in-One Guide to Exam Success!

The synthetic narcotic that has been known to "freeze" addicts is MPTP. MPTP is a synthetic byproduct that was discovered to induce symptoms similar to those of Parkinson's disease when used. Specifically, it can lead to a state resembling 'freezing,' where individuals exhibit a lack of movement and rigidity, akin to the effects seen in advanced Parkinson's disease. This remarkable association is due to MPTP's ability to selectively damage dopamine-producing neurons in the brain, which play a critical role in movement control.

In contrast, Levacetylmethadol is primarily used for treating opioid addiction and pain without the same neurotoxic effects that MPTP has. Oxycodone is a commonly prescribed opioid for pain management but does not lead to the freezing phenomenon. Fentanyl, while highly potent and linked to significant respiratory depression and overdose risks, similarly does not specifically cause the described freezing reaction seen with MPTP. Thus, MPTP stands out as the choice associated with the freezing effect among the options provided.