Objective: To quantify the available evidence for the hypothesis that reduced resistance caused by psychological stress may influence the development of clinical disease in those exposed to an infectious agent.
Methods: We conducted a systematic review and meta-analysis of 27 prospective studies examining the association between psychological stress and subsequent upper respiratory infection (URI).
Results: The results revealed a significant overall main effect of psychological stress on the risk of developing URI (effect size correlation coefficient, 0.21; 95% confidence interval, 0.15-0.27). Further analyses showed that effect sizes for the association did not vary according to type of stress, how URI was assessed, or whether the studies had controlled for preexposure.
Conclusions: The meta-analytical findings confirmed the hypothesis that psychological stress is associated with increased susceptibility to URI, lending support to an emerging appreciation of the potential importance of psychological factors in infectious disease.