One may not logically assume that neurotic personalities have better health than other people. Of the Big Five personality dimensions - openness, extraversion, agreeableness, conscientiousness and neuroticism - one might actually believe that neurotics would fare the worst. Even scientists concede that "neuroticism is usually marked by being moody, nervous, and a worrier, and linked to hostility, depression, and excessive drinking and smoking."

Even still, a study conducted by researchers at the University of Rochester Medical Center found that people with a healthy degree of neuroticism were more likely to have low levels of Interleukin 6, an immune protein. IR-6 is the key because it is an important predictor of the risk of many lifelong diseases, including inflammation linked to arthritis, asthma, some cancers, diabetes, heart disease, and stroke.

The study, published in the journal Brain, Behavior, and Immunity, used data from the National Survey of Midlife Development in the United States. The study examined 1,054 participants from the East Coast, West Coast, and the Midwest. Participants were given a battery of tests in order to establish their level of health, including tests looking for disease-related biomarkers, organ function, and personality quizzes.

Researchers were surprised to find that people who scored moderate to high scores on neuroticism were more likely to have better health. But there was a catch. That finding was true for people who also scored moderate to high scores on conscientiousness as well. These 441 people also tended to have lower body mass indexes and fewer chronic diseases. In fact, the higher people's scores were in both categories, the better their health tended to be.

People who simply received high scores in neuroticism, without the conscientious factor, were less likely to have proper ways of dealing with stress.

The term "healthy neuroticism" first appeared in 2000. Researchers found that conscientious self-discipline made people less likely to indulge in neurotic behaviors like overeating, smoking, and heavy drinking. Incidentally, all of those behaviors affect inflammation, and therefore IR-6 levels.

"Speculation is that healthy neurotics may be hyper-vigilant about their lifestyle and about seeking treatment when a problem arises," said Nicholas Turiano, one of the study researchers, in a statement. "It's their conscientiousness that guides their decisions to prevent disease or quickly get treatment when they don't feel well."