Phenylethylamine overproduction in aggressive psychopaths.

Plasma concentrations of free and conjugated phenylacetic acid, the major metabolite of phenylethylamine, were higher in ten prisoners serving long terms of imprisonment for violent crimes than in pair-matched non-violent control prisoners. Since amphetamine, a compound closely related to phenylethylamine, can reduce aggressiveness in some violent subjects, the increase in phenylethylamine production may be an attempt to compensate for the unknown derangement of function responsible for increased aggression.