ROCHESTER, Minn. -- Your outlook on life not only may help you live longer, but it appears to have an impact on your quality of life. Mayo Clinic researchers say that optimists report a higher level of physical and mental functioning than their pessimist counterparts.

"The wellness of being is not just physical, but attitudinal," said Toshihiko Maruta, M.D., of the Mayo Clinic Department of Psychiatry and Psychology in Rochester and the principal author of the study, which appears in the August issue of Mayo Clinic Proceedings. "How you perceive what goes on around you and how you interpret it may have an impact on your longevity, and it could affect the quality of your later years."

Patients originally assessed in the 1960s with a personality test completed a follow-up self-assessment of their health status 30 years later. In the health survey, pessimists reported poorer physical and mental functioning. The results come two years after a Mayo Clinic study of the data found that optimists live longer than pessimists.

The researchers say, that to their knowledge, the two studies they've done are the first to report on the long-term health implications of explanatory style, an assessment of patients that classifies them as optimists, pessimists or mixed.

Researchers looked at the health survey results reported by 447 patients in the 1990s. This group had originally completed the Minnesota Multiphasic Personality Inventory (MMPI) between 1962 and 1965. The MMPI is an assessment that helps researchers classify personality traits. An optimism and pessimism scale was developed for the MMPI in 1994. Using the scale to determine how to classify the patients, researchers found that 101 were classified as optimistic, 272 as mixed and 74 as pessimistic.

Researchers said pessimists scored below optimists on quality-of-life assessments, and also scored lower than the national average on five of the eight scales that were measured. Those are physical functioning; role limitations, physical; bodily pain; general health perception; vitality; social functioning; role limitations, emotional; and mental health.

"Our study provides documentation for beliefs commonly held by patients and health care practitioners about the importance of optimistic and pessimistic attitudes," Dr. Maruta said. "However, questions remain about the practical significance of these findings for health care practitioners."

Further study of explanatory style, which is a measured assessment, is warranted to make those determinations, Dr. Maruta said. Also, Dr. Maruta says the results might begin to help health care professionals in how they assess and deal with their patients.

"Explanatory style may have implications for prevention, intervention, health care utilization and compliance with treatment regimens," Dr. Maruta said. "Well formulated studies are essential to warrant the extra time, effort and costs associated with efforts to intervene in a patient's explanatory style or to personalize the care specific to explanatory style."

Along with Dr. Maruta, researchers involved with the study include: Robert C. Colligan, Ph.D., Mayo Clinic Department of Psychiatry and Psychology; Michael Malinchoc, M.S., and Kenneth P. Offord, M.S., Mayo Clinic Division of Biostatistics in Rochester.

Mayo Clinic Proceedings is a peer-reviewed and indexed general internal medicine journal, published for more than 75 years by Mayo Foundation. It has a circulation of 130,000 nationally and internationally.

---Mayo Clinic