Abstract
The purpose of this study was to test whether different acute mental stress tests induce differential responses in salivary 3-methoxy-4-hydroxyphenylglycol (MHPG), the principal metabolite of noradrenaline derived from the brain. The participants were ten male healthy volunteers who performed two tasks, the Stroop color word conflict task and serial mental arithmetic (Uchida-Kraepelin Test), on two separate days using a counterbalanced design. Salivary MHPG and subjective stress were measured at baseline, immediately after tasks, and then 10 min later. The two tasks stimulated a similar increase in subjective stress. But salivary MHPG only increased in response to the color word conflict task, and not mental arithmetic. These results suggest that there are specific situational dimensions of mental stress tests that stimulate MHPG and activate the central noradrenergic nervous system.
