Journal of Personality and Social Psychology
1993, Vol. 64, No. 1,131-140
Copyright 1993 by the American Psychological Association, Inc.
0022-3514/93/53.00
Negative Life Events, Perceived Stress, Negative Affect,
and Susceptibility to the Common Cold
Sheldon Cohen, David A. J. Tyrrell, and Andrew P. Smith
After completing questionnaires assessing stressful life events, perceived stress, and negative af-
fect, 394 healthy Ss were intentionally exposed to a common cold virus, quarantined, and moni-
tored for the development of biologically verified clinical illness. Consistent with the hypothesis
that psychological stress increases susceptibility to infectious agents, higher scores on each of the 3
stress scales were associated with greater risk of developing a cold. However, the relation between
stressful life events and illness was mediated by a different biologic process than were relations
between perceived stress and illness and negative affect and illness. That these scales have indepen-
dent relations with illness and that these relations are mediated by different processes challenges
the assumption that perceptions of stress and negative affect are necessary for stressful life events to
influence disease risk.
It is commonly believed that life stressors increase suscepti-
bility to infectious disease. When demands imposed by events
exceed ability to cope, a psychological stress response is elicited
(Lazarus & Folkman, 1984). This response is composed of nega-
tive cognitive and emotional states. In turn, these states are
thought to alter immune function through autonomic nerves
that connect the central nervous system to immune tissue (D. L.
Felten, Felten, Carlson, Olschowka, & Livnat, 1985; S. Y. Felten
& Olschowka, 1987), through the action of hormones whose
release is associated with negative affectivity (Shavit, Lewis,
Terman, Gale, & Liebeskind, 1984), or through stress-elicited
changes in health practices such as smoking and alcohol con-
sumption (Cohen & Williamson, 1991; Kiecolt-Glaser &
Glaser, 198