Impulsivity-related traits are associated with higher white blood cell counts

A chronically elevated white blood cell (WBC) count is a risk factor for morbidity and mortality. The present research tests
whether facets of impulsivity—impulsiveness, excitement-seeking, self-discipline, and deliberation—are associated with chronically
elevated WBC counts. Community-dwelling participants (N = 5,652) from Sardinia, Italy, completed a standard personality questionnaire and provided blood samples concurrently and
again 3 years later. Higher scores on impulsivity, in particular impulsiveness and excitement-seeking, were related to higher
total WBC counts and higher lymphocyte counts at both time points. Impulsiveness was a predictor of chronic inflammation:
for every standard deviation difference in this trait, there was an almost 25% higher risk of elevated WBC counts at both
time points (OR = 1.23, 95% CI = 1.10–1.38). These associations were mediated, in part, by smoking and body mass index. The
findings demonstrate that links between psychological processes and immunity are not limited to acute stressors; stable personality
dispositions are associated with a chronic inflammatory state.