***AS FEATURED ON NPR'S TALK OF THE NATION***

Imagine the worst thing in the world. Picture it. Construct it, carefully and deliberately in your mind. Be careful not to omit anything. Imagine it happening to you, to the people you love. Imagine the worst thing in the world.

Now try not to think about it.

This is what it is like for Fletcher Wortmann. In his brilliant memoir, the author takes us on an intimate journey across the psychological landscape of OCD, known as the "doubting disorder," as populated...