Joe Biden's osteopathic doctor pleads the Fifth on mental acuity: DO vs MD Biden's former White House doctor, Kevin O'Connor, DO, faced questions from House GOP members investigating the former president's cognitive decline. Here's the difference between a DO and an MD. Original Source: https://www.foxnews.com/health/joe-bidens-osteopathic-doctor-pleads-fifth-mental-acuity-do-vs-md
