This paper from the CDC gives comparisons of drug overdose deaths between 2017 and 2018 and highlights the emergence of a polysubstance crisis.
Wilson, N., Kariisa, M., Seth, P., Smith, H., Davis, N.L. (2020). Drug and Opioid-Involved Overdose Deaths — United States, 2017–2018. MMWR Morb Mortal Wkly Rep, 69, 290–297.