Objective: It has been hypothesized that people who typically report experiencing negative emotions are at greater risk for disease and those who typically report positive emotions are at less risk. We tested these hypotheses for host resistance to the common cold.
Methods: Three hundred thirty-four healthy volunteers aged 18 to 54 years were assessed for their tendency to experience positive emotions such as happy, pleased, and relaxed; and for negative emotions such as anxious, hostile, and depressed. Subsequently, they were given nasal drops containing one of two rhinoviruses and monitored in quarantine for the development of a common cold (illness in the presence of verified infection).
Results: For both viruses, increased positive emotional style (PES) was associated (in a dose-response manner) with lower risk of developing a cold. This relationship was maintained after controlling for prechallenge virus-specific antibody, virus-type, age, sex, education, race, body mass, and season (adjusted relative risk comparing lowest-to-highest tertile = 2.9). Negative emotional style (NES) was not associated with colds and the association of positive style and colds was independent of negative style. Although PES was associated with lower levels of endocrine hormones and better health practices, these differences could not account for different risks for illness. In separate analyses, NES was associated with reporting more unfounded (independent of objective markers of disease) symptoms, and PES with reporting fewer.
Conclusions: The tendency to experience positive emotions was associated with greater resistance to objectively verifiable colds. PES was also associated with reporting fewer unfounded symptoms and NES with reporting more.