These days anything that's widespread might be called an "epidemic." Violence, obesity, opioids, even loneliness. But in the public health space, the label "epidemic" carries special significance beyond that - it's a disease that's widespread - and usually contagious, too. How does thinking about social issues as epidemics change the way we approach them? We'll explore the pros and cons with first responders on the front line of each of those epidemics: What changes if we think of opioid addiction as a disease rather than a crime or character flaw? In what ways is loneliness like a disease - and what's the prescription? Obesity got official epidemic status in America in the '90s. And yet, obesity rates have only increased, so what's to gain by viewing violence as a disease epidemic?