Optimism May Enhance Immune Function

In that previous studies have suggested that people who are optimistic about their health tend to have better health, Suzanne C. Segerstrom, from the University of Kentucky (Kentucky, USA), and colleagues investigated the nature and mechanisms of how optimism potentially exerts this effect.  The team enrolled 124 first-year law school students.  Assessing them at five times over six months, each subject was surveyed as to their levels of optimism and injected with a substance to summon an immune response; two days later, the subjects returned to have the injection site measured. The researchers considered a larger bump in the skin to imply a stronger immune response, thereby a marker of cell-mediated immunity. The team concluded that:  “Changes in optimism correlated with changes in [cell-mediated immunity]. Likewise, changes in optimism predicted changes in positive and, to a lesser degree, negative affect, but the relationship between optimism and immunity was partially accounted for only by positive affect. This dynamic relationship between expectancies and immunity has positive implications for psychological interventions to improve health, particularly those that increase positive affect.”