Here’s a striking piece of information: Social isolation is as deadly as smoking up to 15 cigarettes a day. Loneliness is an epidemic in the United States. We’re approaching one year since the U.S. Surgeon General released a groundbreaking report on loneliness and isolation. Two researchers joined MPR News host Angela Davis to help us understand why so many of us feel lonely, and why our mental health is so closely tied to serious physical health impacts. They’ll also talk about practical strategies to help us feel better. Because lots of us feel this way — at least half of us have measurable levels of loneliness. Guests:   Stephanie Hooker is an assistant professor at the University of Minnesota’s School of Family Medicine and Community Health. Roxanne Prichard is a professor of neuroscience and psychology at the University of St. Thomas.