The fourth wave of the US opioid epidemic and its implications for the rural US: A federal perspective.

The current opioid epidemic in the United States has been characterized as having three waves: prescription opioid use, followed by heroin use, and then use of synthetic opioids (e.g., fentanyl), with early waves affecting a population that was younger, less predominantly male, and more likely to be Caucasian and rural than in past opioid epidemics. A variety of recent data suggest that we have entered a fourth wave which can be characterized as a stimulant/opioid epidemic, with mental illness co-morbidities being more evident than in the past. Stimulant use has introduced new complexities in terms of behavioral consequences (e.g., neurological deficits, suicidal ideation, psychosis, hostility, violence), available treatments, and engagement into services. These compound existing issues in addressing the opioid epidemic in rural areas, including the low density of populations and the scarcity of behavioral health resources (e.g., fewer credentialed behavioral health professionals, particularly those able to prescribe Buprenorphine). Considerations for addressing this new wave are discussed, along with the drawbacks of a wave perspective and persistent concerns in confronting drug abuse such as stigma.