Volume 24 of this Update from the UN Office of Drugs and Crime says that the current opioid crisis is a far-reaching drug and public health policy issue affecting several geographical regions. Despite some progress, the crisis continues both to expand geographically and to deepen in complexity with the emergence of a new generation of new psychoactive substances (NPS) with opioid effects, including substances belonging to chemical structural classes which were not significantly present on illicit drug markets previously. This evolution signals the potential development of similar new substances which may exacerbate the already significant challenges.
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