An Iowa man is so bothered by the political climate that his psychologist says he asked for a higher dosage of his anxiety medication. A Chicago woman is so uneasy about politics that she has needed two dental implants to deal with her teeth-grinding habit. And a New York woman says she suffered her first flare-up of multiple sclerosis in 10 years due to political angst.

Americans are stressed and politics is a major cause, according to psychologists, psychiatrists and recent surveys.

A...