Some aspects of basic psychopharmacology: the trace amines.

1. Some recent research on the behavioural effects of phenylethylamine and some recent data implicating the trace amines in schizophrenia, agoraphobia and aggression are briefly outlined. 2. Phenylethylamine produces in mice a distinctive hyperactivity syndrome consisting of two phases; it appears to act via dopamine and 5-hydroxytryptamine on different components of these stereotypies. 3. Urinary unconjugated tryptamine, and meta- and para-tyramine appear to be excreted in reduced amounts in schizophrenia and bipolar depression. 4. The blood levels of the trace acids phenylacetic and meta- and para-hydroxyphenylacetic are reduced in schizophrenia. 5. Blood levels of conjugated phenylacetic and unconjugated para-hydroxyphenylacetic acid are reduced in violent as opposed to non-violent offenders. 6. The neuromodulatory role of the trace amines and their possible involvement in components of behaviour and certain mental disorders are discussed.