Neuroticism predicts normal variability in the number of circulating leucocytes

Abstract

Exposure to Stressors and states of high negative affect have been associated with a variety of deviations in immune function, including a higher white blood cell (leucocyte) count in the peripheral circulation. Such a higher leucocyte count may be a consequence of increased sympathetic nervous system activity, since catecholamines have been shown to increase the leucocyte count. The present study explored this hypothesis by examining the relationship between neuroticism, an aspect of personality associated with sympathetic reactivity, and the number of circulating leucocytes in a sample of healthy volunteers. Neuroticism was found to be positively correlated with leucocyte count after controlling for the effect of gender, history of allergy, current use of medicines, alcohol consumption, and lifetime use of illicit drugs. Further analyses indicated that specific facets of neuroticism (e.g. irritability, anxiety, depression) appeared to be differentially related to counts of the various cell types that make up the leucocyte population. These findings are briefly discussed with respect to possible significance for immune response dynamics and health maintenance.