Under certain circumstances neuroticism can be good for your health, according to a University of Rochester Medical Center study showing that some self-described neurotics also tended to have the lowest levels of Interleukin 6 (IL-6), a biomarker for inflammation and chronic disease.

Researchers made the preliminary discovery while conducting research into how psychosocial factors such as personality traits influence underlying biology, to predict harmful conditions like inflammation.

Known as one of the "Big 5" traits, neuroticism is usually marked by being moody, nervous, and a worrier, and linked to hostility, depression, and excessive drinking and smoking. The scientific literature is rife with findings that extreme anxiety and self-medicating with alcohol and other substances due to neuroticism are detrimental to long-term health. The other four traits are openness (creative, curious, broad-minded), extraversion (outgoing, friendly, talkative), agreeableness (helpful, warm, sympathetic), and conscientiousness (organized, responsible, hardworking).

Nicholas A. Turiano, Ph.D., a post-doctoral fellow in the URMC Department of Psychiatry, wondered about a gray area -- those people with average-to-high levels of neuroticism who are also conscientious. Exhibiting higher levels of conscientiousness as well as neuroticism points to folks who tend to be high-functioning in society, very organized, goal-oriented, planners, and more likely to be reflective.

"These people are likely to weigh the consequences of their actions, and therefore their level of neuroticism coupled with conscientiousness probably stops them from engaging in risky behaviors," said Turiano, whose study is published online by the journal Brain, Behavior, and Immunity.

Turiano and co-authors sought an objective way to test their hypothesis that "healthy neuroticism" could be protective. They tapped into the National Survey of Midlife Development in the U.S. (MIDUS) database, a sampling of adults (1,054 participants) from the West Coast, East Coast, and Midwest. Participants took part in a full clinic-based health evaluation, including tests for disease-related biomarkers, physiological function, and personality traits.

Interleukin 6, an important immune protein, is easily measured by a fasting blood test. It was one of several pieces of data collected and available in the MIDUS database, because it provides an accurate assessment of conditions linked to inflammation such as heart disease, stroke, asthma, arthritis, diabetes, and some cancers.

Researchers studied many pathways between personality, health behaviors, and chronic disease, but the neuroticism-conscientiousness interaction emerged among 441 individuals who scored moderate to high on both traits. And, the higher a person scored in both conscientiousness and neuroticism, the lower their levels of IL-6. This group also had lower body-mass index scores and fewer diagnosed chronic health conditions, results showed.

The term "healthy neuroticism" was coined in 2000 when other researchers first described how conscientiousness may provide the dose of self-discipline that reduces unhealthy neurotic behaviors like overeating, smoking, and drinking too much alcohol -- all of which have direct or indirect consequences for inflammation. In contrast, a neurotic person who scores low in conscientiousness may not have healthy avenues to deal with stress, the paper said.

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

However, Turiano cautions that more research is needed before scientists can draw firm conclusions. Simply labeling certain traits as "good" versus "bad" as they relate to health is not sufficient for a full understanding of the personality-health link.

"Future studies will try to figure out who are the healthy neurotics and why they are healthier," Turiano said. "Eventually, the clinical application might allow us to identify patients at high risk for chronic inflammation, and therefore have an increased risk of health problems and death."