There's a lot to be anxious about — an upcoming job interview, a first date or perhaps a big presentation at work. For some, anxiety can be much more than just sweaty palms and quivering hands. It can be a debilitating condition with severe physical and mental effects.
The Anxiety and Depression Association of America estimates that nearly 40 million American adults suffer from a wide range of anxiety disorders — from acute nervousness and increased heart rate, to full-on panic attacks.
In his new book Monkey Mind, Daniel Smith documents his experiences with a kind of anxiety that results in panic attacks, bouts of insomnia and thoughts of "existential ruin." He talks with NPR's John Donvan about the many layers of his condition and how he's learned to live with it.