I am a huge fan of Ezra Klein and his podcasts. In this recent one, “That Anxiety You’re Feeling? It’s a Habit You Can Unlearn,” he interviews Jud Brewer, an associate professor of psychiatry at Brown University and the Director of Research and Innovation at the Mindfulness Center. His new book, “Unwinding Anxiety: New Science Shows How to Break the Cycles of Worry and Fear to Heal Your Mind,” applies that research to anxiety, which he understands as a kind of addiction. As with any addiction, you must understand its rewards in order to begin addressing it.