The present study was undertaken to further explore the potential neuropsychological information associated with baseline plasma levels of catecholamines and dopamine D3 receptor (DRD3) mRNA expression in peripheral blood lymphocytes (PBL). Baseline plasma norepinephrine and epinephrine levels and PBL DRD3 mRNA expression were compared with performance in the Wisconsin Card Sorting Test (WCST) in n=79 healthy volunteers (mean+/-S.D. age: 24.1+/-3.2 years, 34 males). After correction for multiple testing, we found that baseline plasma epinephrine levels predicted WCST total number of errors (Spearman's rho=-0.36, p<0.05), number of perseverative responses (Spearman's rho=-0.36, p<0.05) and percent conceptual level responses (Spearman's rho=0.37, p<0.05). Plasma norepinephrine levels and PBL DRD3 mRNA expression did not predict WCST scores, but PBL DRD3 mRNA expression correlated negatively with plasma epinephrine levels (Spearman's rho=-0.45, p<0.001). Further studies should be undertaken to explore possible neurophysiological links between plasma epinephrine levels and the neurobiology underlying cognitive performance.