Optimists don't always fare better than pessimists in their immunologic response to stress

Optimists don't always fare better than pessimists in their immunologic response to stress, a new review of studies finds.

The difference seems to be based on the degree of stress facing the optimist and the degree to which a pessimist avoids the problem, according to an article in the current issue of the journal Brain, Behavior, and Immunity by Suzanne Segerstrom, Ph.D., of the University of Kentucky.

“There is sometimes a physiological cost to be paid for the optimistic strategy of engaging difficult stressors rather than disengaging and withdrawing,” Segerstrom writes, instancing the higher levels of the stress hormone cortisol and lower levels of cellular immunity in people with HIV.

The studies she reviewed were mixed on the overall effects of optimism on immunity, but Segerstrom concludes that when stressors are easy, optimism can have a positive effect on the immune system. When stressors are difficult, however, some studies have shown that optimists are less likely to disengage from or avoid the problem, which may have a negative effect on their immune systems.

“… When circumstances are easy or straightforward, optimism will be positively related to immunity because engagement can lead to termination of the stressor,” Segerstrom postulates. “However, when circumstances are difficult or complex, optimism will be negatively related to immunity because it leads to ongoing engagement with persistent stressors.”

Put another way, when an optimist is faced with a serious health or other problem that cannot be resolved, the disappointment — and thus the negative immune response — is greater than that of the pessimist, who did not have high hopes in the first place or who might have simply avoided the issue.

However, John T. Cacioppo, Ph.D., director of the Center for Cognitive and Social Neuroscience at the University of Chicago, says that this does not mean that seriously ill patients should just disengage. “Based on the study, this would be far too general a conclusion to make,” Cacioppo says. “Disengaging when you can't do anything about the stressor can be protective, but disengaging when you are confronted with a difficult stressor about which you can do something would not necessarily be beneficial.”

Segerstrom agrees that, based on the study, seriously ill patients should not be told to lose their optimism and disengage when dealing with their disease but rather to be aware that engagement with difficult stressors, an optimistic strategy, can consume energy valuable to the immune system.

“I think one thing that you can reasonably say is … that optimism involves a willingness to expend a lot of energy to reach your goals,” Segerstrom says. “So the advice should be to conserve some energy for your immune system to work if you have a condition that requires a lot of immune activity.”

“There are well-known psychological disadvantages to disengagement, such as depression and prolonged stress that may actually prolong the effects of the stressor,” Segerstrom concludes. “We generally do not see advantages to disengagement, especially in the long term. In the absence of evidence that engagement shows any long-term harm, it’s hard to justify telling people to disengage from the things that are important to them.”