Urinary phenylethylamine correlates positively with hypomania, and negatively with depression, paranoia, and social introversion on the MMPI.

It has been suggested that phenylethylamine (PEA) may play a role in the modulation of affective behavior. The aim of the present study was to test this hypothesis. Urinary PEA excretion was determined in 32 drug-free healthy volunteers, and the MMPI was used for personality assessment. In support of this hypothesis, a significant positive correlation between PEA and hypomania (r = 0.50; P less than 0.05) and a significant negative correlation between PEA and depression (r = -0.58; P less than 0.01) was observed in the female subgroup. Furthermore, PEA correlated significantly negatively with hypochondriasis (r = -0.65; P less than 0.01), paranoia (r = 0.49; P less than 0.05), and social introversion (r = -0.60; P less than 0.05). These results are the first evidence in normal individuals either that PEA itself might play a role in the modulation of affective behavior, or alternatively that PEA could be related to mechanisms responsible for the modulation of affective behavior.