Plasma vanillylmandelic acid level as an index of psychological stress response in normal subjects

The relationships between psychological stress responses and plasma levels of vanillylmandelic acid (VMA), 3-methoxy-4-hydroxyphenylglycol (MHPG), homovanillic acid (HVA), and 5-hydroxyindolacetic acid (5-HIAA) were investigated in normal volunteers. Two questionnaires were used to measure stress: the Psychological Stress Response Scale (PSRS) and the State-Trait Anxiety Inventory (STAI). Plasma levels of VMA - but not MHPG, HVA, and 5-HIAA - showed significant positive correlations with PSRS emotional and cognitive-behavioral stress and STAI state anxiety, Significant positive correlations were also found between plasma levels of VMA and MHPG and psychological stress responses measured repeatedly in a longitudinal study of an Olympic swimmer. Plasma VMA measurements, which reflect the level of activity of the peripheral sympathetic nervous system, may provide a useful biochemical index of psychological stress responses in normal subjects.