The Mask of Sanity is an American novel by Jacob M. Appel, published by The Permanent Press in 2017.

[3] Dr. Jeremy Balint is an up-and-coming cardiologist who discovers that his wife Amanda is having an affair with his fellow physician Warren Sugarman.

[5] Bruce DeSilva in The Washington Post described the novel as "both a suspenseful yarn and a chilling portrait of the mind of a high-functioning sociopath.

"[6] Publishers Weekly praised the novel's "matter-of-fact, nonjudgmental prose" and described the volume as "deeply unsettling.

"[8] Reviewing the novel in Amsterdam Quarterly, Bryan Monte wrote "The Mask of Sanity is full of surprises and will keep the reader wondering if Balint will be caught all the way to the very end of the story.