Phenylethylamine Hypothesis of Affective Behavior

The authors present experimental evidence to support the hypothesis that 2-phenylethylamine (PEA) and its metabolites modulate affective behavior. Values for the urinary excretion of PEA were lower for 71 percent of a group of depressed patients than the lowest values obtained from control subjects, which suggests that a large percentage of endogenous depressions may be due to a deficit of PEA in the brain. Animal studies indicate that an increase in the levels of PEA in the brain may be partly responsible for the elation induced by marijuana and for the therapeutic action of antidepressant agents.