Changes in daily event frequency precede episodes of physical symptoms.

Although numerous reports show a direct relationship between life stress and various physical and psychological symptoms, methodological shortcomings have limited the significance of these studies. We present data from a prospective investigation of daily life experiences to provide more convincing evidence about this relationship. Undesirable events increased and desirable events decreased in frequency three to four days prior to the onset of an episode of symptoms. This finding and other physiological reports suggest mediation of this effect by suppression of secretory IgA.