Optimism Boosts the Immune System

Feeling better about the future might help you feel better for real. In a new study, psychological scientists Suzanne Segerstrom of the University of Kentucky and Sandra Sephton of the University of Louisville studied how law students' expectations about the future affected their immune response. Their conclusions: Optimism may be good for your health.

Other studies have found that people who are optimistic about their health tend to do better. For example, people who are optimistic about heart transplant surgery recover better from that gruelling operation. But it's not clear how optimism affects your health - or whether pessimism makes you less healthy.

For this study, reported in Psychological Science, a journal of the Association for Psychological Science, the researchers recruited first-year law students by sending them a packet during the summer before classes started. The 124 students that participated in the research were studied at five times over six months. Each time, they answered questions about how optimistic they felt about law school. Then they were injected with material that should summon an immune response and two days later, they came back to have the injection site measured. A larger bump in the skin means a stronger immune response. Immune systems are many-faceted; this test only measures the strength of the part that is responsible for fighting viral infections and some bacterial infections.

The students' general outlook on life - whether they had an optimistic disposition - didn't account for the differences in immune responses between students. But as each student's expectations about law school waxed and waned, their immune response followed along. At more optimistic times, they'd have bigger immune responses; at a more pessimistic time, a more sluggish immune response. So, being optimistic about success in a specific, important domain may promote better immunity against some infections.

Of course, the law students often have good reason to be optimistic or pessimistic; by a few months into the first semester, they've gotten some grades back and started to figure out if they're good or bad at law school. "I don't think that I would advise people that they should revise their expectations to be unrealistic," says Segerstrom. "But if people have slightly more positive views of the future than is actually true, that's adaptive."


Contact: Sylvain-Jacques Desjardins
University of Montreal
Men and women respond differently to stress
University of Montreal study on physiological responses to stress

Montreal, March 23, 2010 - Age and gender play a major role in how people respond to stress, according to a new study on 20-to-64-year-olds. Published in the journal Psychophysiology, the investigation was led by scientists from the Université de Montréal and the Montreal Heart Institute in collaboration with colleagues from the Université du Québec à Montréal and McGill University.

"Our findings suggest that women who are more defencive are at increased cardiovascular risk, whereas low defensiveness appears to damage the health of older men," says Bianca D'Antono, a professor at the Université de Montréal Department of Psychiatry and a Montreal Heart Institute researcher.

Defensiveness is a trait characterised by avoidance, denial or repression of information perceived as threatening. In women, a strong defencive reaction to judgment from others or a threat to self-esteem will result in high blood pressure and heart rate. Contrarily, older men with low defencive reactions have a higher cardiovascular rates.

The study was conducted on 81 healthy working men and 118 women. According to Dr. Jean-Claude Tardif a Université de Montréal professor and Montreal Heart Institute researcher, the physiological response to stress in women and older men is linked to this desire of maintaining self-esteem and securing social bonds.

"The sense of belonging is a basic human need," says D'Antono. "Our findings suggest that socialisation is innate and that belonging to a group contributed to the survival of our ancestors. Today, it is possible that most people view social exclusion as a threat to their existence. A strong defencive reaction is useful to maintain one's self-esteem faced with this potential threat."

As part of the experiment, participants completed four tasks of varying stress levels. The first task involved reading a neutral text on Antarctica's geography before a person of the same sex. The second and third tasks involved role-playing in which participants followed a script where they were sometimes agreeable and sometimes aggressive. The final task involved a non-scripted debate on abortion.

Heart rate and blood pressure were measured during each of these tasks as was the level of cortisol in saliva. Results showed that women and older men had elevated cardiovascular, autonomic and endocrine responses to stress - all potentially damaging to their health. The research team cautions, however, that more studies are needed to evaluate the long-term effects of defensiveness and its association to stress response patterns in disease development.

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