Abstract
The anomalous relationship between secretory immunoglobulin A (sIgA) concentration in saliva and psychosocial factors is considered to be caused by circadian variations and acute stress-induced variations in sIgA levels. To prevent such variations in sIgA levels, we investigated the relationship between sIgA concentration that was estimated upon awakening and daily events and moods. University students (N = 54) were instructed to collect their saliva samples immediately upon awakening and again after 2 weeks. On the day before saliva collection, the students completed questionnaires on their daily events and moods over the past 2 weeks. Correlations of daily events and moods and sIgA concentration changes from the first and second measurement sessions indicated that participants who reported a higher frequency of daily negative events and depressive mood exhibited lower sIgA concentrations (r =-.294 and-.283, respectively). Moreover, negative events in male participants and depressive mood in female participants were negatively correlated with sIgA concentration, whereas positive events and mood in female participants were positively correlated with sIgA concentration. We clearly demonstrated that negative and positive psychosocial factors caused a decrease and increase in sIgA concentration in saliva, respectively. (Japanese Journalof Physiological Psychology and Psychophysiology, 25 (3) : 237-244, 2007.)
