An individual with opioid use disorder who returns to her old drug-using habits after incarceration is most likely to experience a collapse due to which factor?

The correct answer is that loss of tolerance is the key factor contributing to the individual’s potential for overdose upon returning to opioid use after a period of abstinence, such as incarceration. When someone who has been using opioids regularly stops, such as during a prison sentence, their body may lose the adaptations it had developed in response to the drug. This includes a decreased tolerance to opioids, meaning that their body may not be able to handle the same amount of the drug as it could before.

If the individual resumes using opioids at their previous dosage after a period of cessation, they are at a significantly higher risk for overdose because their body can no longer tolerate that amount. The reintroduction of opioids into a system that has lost its tolerance can quickly lead to respiratory depression, coma, or death.

While increased drug purity can indeed pose a risk for overdose, particularly if the individual is not experienced with the current substance’s potency, the primary concern following a return to substance use after abstinence is the loss of tolerance. Contaminants in the heroin or interactions with other medications are factors that may contribute to risk but are not as directly impactful on the reintroduction of drugs after a period of no use as loss of tolerance.