Final answer:
The number of problem drug users as per the United Nations Office on Drugs and Crime is not provided, but the text details the serious opioid crisis in the U.S., the drastic rise in prescription painkiller usage, the switch to cheaper and more dangerous substances, and changing public opinion towards drug users and legalization.
Step-by-step explanation:
The United Nations Office on Drugs and Crime has not been explicitly cited in the provided reference for a specific number of people who are considered problem drug users. However, the information provided highlights the severity and impact of the opioid crisis in the United States. It is mentioned that an average of 130 people died each day due to an opioid overdose in 2019, indicating the significant number of opioid-addicted individuals. The epidemic saw an increase in the medical use of prescription painkillers with a three-fold increase from 1991 to 2011, which has since led many to switch to cheaper alternatives like heroin or synthetic opioids. The shift to more deadly substances such as Fentanyl, often linked to crime syndicates, has contributed to a steep rise in opioid overdose deaths. Additionally, public opinion on drug use has evolved, with a majority of Americans favoring the legalization of marijuana, which reflects changing perceptions towards drug users and drug policy.