Polysubstance use disorder is a mental health condition in which someone uses more than one substance at the same time or within a short period of time, despite a pattern of negative effects.

A massive survey recently released by a national drug-testing company strongly suggests we are well into the “fourth wave” of the opioid crisis. The three previous waves were driven by 1) prescription ...

Polysubstance use has become a defining feature of the U.S. overdose crisis in the past decade. While not every overdose involves multiple substances, a significant and growing proportion includes ...