Immunological variability associated with experimentally-induced positive and negative affective states.

Functional and phenotypic immunological parameters were examined immediately before, after, and 30 minutes after experimentally-induced short-term positive (happiness) and negative (anxiety, depression) affective states and a neutral state, in five healthy subjects. Results indicated that all affective states induced more immune fluctuations (regardless of the direction) than the neutral state. Furthermore, among the affective states, anxiety induced the most immunological variability and depression the least.