In this helpful guide, psychiatrist Brewer (The Craving Mind) draws on research on addiction and bad habits to suggest ways to deal with anxiety. Citing the definition of addiction--"continued use despite adverse consequences"--Brewer argues that anxiety and addiction share similar patterns and can be addressed using similar principles: identifying a habit loop, then using mindfulness to change the way one's brain values the behavior. "If you really pay careful and close attention," Brewer writes, "...and you see that a behavior is not rewarding right now, I promise you that you will start to get less excited about doing it again." Instead, one can give the brain a "bigger better offer": to bring curiosity and mindfulness toward one's actions. The writing is casual without being simplistic ("This is a pretty neat hack of your brain's reward-based learning system") and includes testimonials from patients and users of mindfulness apps developed by Brewer. These evidence-based, structured recommendations will be useful to anyone who feels caught in a negative loop. (Mar.)